[meteorite-list] Dawn Mission Extended at Ceres
https://www.jpl.nasa.gov/news/news.php?feature=6980 Dawn Mission Extended at Ceres Jet Propulsion Laboratory October 19, 2017 NASA has authorized a second extension of the Dawn mission at Ceres, the largest object in the asteroid belt between Mars and Jupiter. During this extension, the spacecraft will descend to lower altitudes than ever before at the dwarf planet, which it has been orbiting since March 2015. The spacecraft will continue at Ceres for the remainder of its science investigation and will remain in a stable orbit indefinitely after its hydrazine fuel runs out. The Dawn flight team is studying ways to maneuver Dawn into a new elliptical orbit, which may take the spacecraft to less than 120 miles (200 kilometers) from the surface of Ceres at closest approach. Previously, Dawn's lowest altitude was 240 miles (385 kilometers). A priority of the second Ceres mission extension is collecting data with Dawn's gamma ray and neutron spectrometer, which measures the number and energy of gamma rays and neutrons. This information is important for understanding the composition of Ceres' uppermost layer and how much ice it contains. The spacecraft also will take visible-light images of Ceres' surface geology with its camera, as well as measurements of Ceres' mineralogy with its visible and infrared mapping spectrometer. The extended mission at Ceres additionally allows Dawn to be in orbit while the dwarf planet goes through perihelion, its closest approach to the Sun, which will occur in April 2018. At closer proximity to the Sun, more ice on Ceres' surface may turn to water vapor, which may in turn contribute to the weak transient atmosphere detected by the European Space Agency's Herschel Space Observatory before Dawn's arrival. Building on Dawn's findings, the team has hypothesized that water vapor may be produced in part from energetic particles from the Sun interacting with ice in Ceres' shallow surface.Scientists will combine data from ground-based observatories with Dawn's observations to further study these phenomena as Ceres approaches perihelion. The Dawn team is currently refining its plans for this next and final chapter of the mission. Because of its commitment to protect Ceres from Earthly contamination, Dawn will not land or crash into Ceres. Instead, it will carry out as much science as it can in its final planned orbit, where it will stay even after it can no longer communicate with Earth. Mission planners estimate the spacecraft can continue operating until the second half of 2018. Dawn is the only mission ever to orbit two extraterrestrial targets. It orbited giant asteroid Vesta for 14 months from 2011 to 2012, then continued on to Ceres, where it has been in orbit since March 2015. The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: https://dawn.jpl.nasa.gov/mission More information about Dawn is available at the following sites: https://www.nasa.gov/dawn https://dawn.jpl.nasa.gov News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, Calif. (818) 354-6425 elizabeth.lan...@jpl.nasa.gov 2017-275 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] This is a Test: Asteroid Tracking Network Observes Close Approach (Asteorid 2012 TC4)
https://www.jpl.nasa.gov/news/news.php?feature=6969 This is a Test: Asteroid Tracking Network Observes Close Approach Jet Propulsion Laboraotry October 10, 2017 On Oct. 12 EDT (Oct. 11 PDT), a small asteroid designated 2012 TC4 will safely pass by Earth at a distance of approximately 26,000 miles (42,000 kilometers). This is a little over one tenth the distance to the Moon and just above the orbital altitude of communications satellites. This encounter with TC4 is being used by asteroid trackers around the world to test their ability to operate as a coordinated international asteroid warning network. 2012 TC4 is estimated to be 50 to 100 feet (15 to 30 meters) in size. Orbit prediction experts say the asteroid poses no risk of impact with Earth. Nonetheless, its close approach to Earth is an opportunity to test the ability of a growing global observing network to communicate and coordinate its optical and radar observations in a real scenario. Oct. 11, 2017 movie of asteroid 2012 TC4 using the 1.0-meter Kiso Schmidt telescope in Nagano, Japan. Credit: Kiso Observatory, the University of Tokyo This asteroid was discovered by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) in Hawaii in 2012. Pan-STARRS conducts a near-Earth object (NEO) survey funded by NASA's NEO Observations Program, a key element of NASA's Planetary Defense Coordination Office. However, 2012 TC4 traveled out of the range of asteroid-tracking telescopes shortly after it was discovered. Based on the observations they were able to make in 2012, asteroid trackers predicted that it should come back into view in the fall of 2017. Observers with the European Space Agency and the European Southern Observatory were the first to recapture 2012 TC4, in late July 2017, using one of their large 8-meter aperture telescopes.Since then, observers around the world have been tracking the object as it approaches Earth and reporting their observations to the Minor Planet Center. This "test" of what has become a global asteroid-impact early-warning system is a volunteer project, conceived and organized by NASA-funded asteroid observers and supported by the NASA Planetary Defense Coordination Office (PDCO). As explained by Michael Kelley, program scientist and NASA PDCO lead for the TC4 observation campaign, "Asteroid trackers are using this flyby to test the worldwide asteroid detection and tracking network, assessing our capability to work together in response to finding a potential real asteroid-impact threat." No asteroid currently known is predicted to impact Earth for the next 100 years. Asteroid TC4's closest approach to Earth will be over Antarctica at 1:42 AM EDT on Oct. 12 (10:42 p.m. PDT on Oct. 11). Tens of professionally run telescopes across the globe will be making ground-based observations in wavelengths from visible to near-infrared to radar. Amateur astronomers may contribute more observations, but the asteroid will be very difficult for backyard astronomers to see, as current estimates are that it will reach a visual magnitude of only about 17 at its brightest, and it will be moving very fast across the sky. Many of the observers who are participating in this exercise are funded by NASA's NEO Observations Program, but observers supported by other countries' space agencies and space institutions around the world are now involved in the campaign. Vishnu Reddy, an assistant professor at the University of Arizona's Lunar and Planetary Laboratory in Tucson, is leading the 2012 TC4 campaign. Reddy is principal investigator for a NASA-funded near-Earth asteroid characterization project. "This campaign is a team effort that involves more than a dozen observatories, universities and labs around the globe so we can collectively learn the strengths and limitations of our near-Earth object observation capabilities," he said. "This effort will exercise the entire system, to include the initial and follow-up observations, precise orbit determination, and international communications." In September, asteroid observers were able to conduct a "pre-test" of coordinated tracking of the close approach of a much larger asteroid known as 3122 Florence. Florence, one of the largest known NEOs, at 2.8 miles (4.5 kilometers) in size, passed by Earth on Sept. 1 at 18 times the distance to the Moon. Coordinated observations of this asteroid revealed, among other things, that Florence has two moons. News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 a...@jpl.nasa.gov 2017-264 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Study Yields Clues to Possible Cradle of Life
https://www.jpl.nasa.gov/news/news.php?feature=6966 Mars Study Yields Clues to Possible Cradle of Life Jet Propulsion Laboratory October 6, 2017 Fast Facts: * A long-gone sea on southern Mars once held nearly 10 times as much water as all of North America's Great Lakes combined, a recent report estimates. * The report interprets data from NASA's Mars Reconnaissance Orbiter as evidence that hot springs pumped mineral-laden water directly into this ancient Martian sea. * Undersea hydrothermal conditions on Mars may have existed about 3.7 billion years ago; undersea hydrothermal conditions on Earth at about that same time are a strong candidate for where and when life on Earth began. * The report adds an important type of wet ancient Martian environment to the diversity indicated by previous findings of evidence for rivers, lakes, deltas, seas, groundwater and hot springs. The discovery of evidence for ancient sea-floor hydrothermal deposits on Mars identifies an area on the planet that may offer clues about the origin of life on Earth. A recent international report examines observations by NASA's Mars Reconnaissance Orbiter (MRO) of massive deposits in a basin on southern Mars. The authors interpret the data as evidence that these deposits were formed by heated water from a volcanically active part of the planet's crust entering the bottom of a large sea long ago. "Even if we never find evidence that there's been life on Mars, this site can tell us about the type of environment where life may have begun on Earth," said Paul Niles of NASA's Johnson Space Center, Houston. "Volcanic activity combined with standing water provided conditions that were likely similar to conditions that existed on Earth at about the same time -- when early life was evolving here." Mars today has neither standing water nor volcanic activity. Researchers estimate an age of about 3.7 billion years for the Martian deposits attributed to seafloor hydrothermal activity. Undersea hydrothermal conditions on Earth at about that same time are a strong candidate for where and when life on Earth began. Earth still has such conditions, where many forms of life thrive on chemical energy extracted from rocks, without sunlight. But due to Earth's active crust, our planet holds little direct geological evidence preserved from the time when life began. The possibility of undersea hydrothermal activity inside icy moons such as Europa at Jupiter and Enceladus at Saturn feeds interest in them as destinations in the quest to find extraterrestrial life. Observations by MRO's Compact Reconnaissance Spectrometer for Mars (CRISM) provided the data for identifying minerals in massive deposits within Mars' Eridania basin, which lies in a region with some of the Red Planet's most ancient exposed crust. "This site gives us a compelling story for a deep, long-lived sea and a deep-sea hydrothermal environment," Niles said. "It is evocative of the deep-sea hydrothermal environments on Earth, similar to environments where life might be found on other worlds -- life that doesn't need a nice atmosphere or temperate surface, but just rocks, heat and water." Niles co-authored the recent report in the journal Nature Communications with lead author Joseph Michalski, who began the analysis while at the Natural History Museum, London, andco-authors at the Planetary Science Institute in Tucson, Arizona, and the Natural History Museum. The researchers estimate the ancient Eridania sea held about 50,000 cubic miles (210,000 cubic kilometers) of water. That is as much as all other lakes and seas on ancient Mars combined and about nine times more than the combined volume of all of North America's Great Lakes. The mix of minerals identified from the spectrometer data, including serpentine, talc and carbonate, and the shape and texture of the thick bedrock layers, led to identifying possible seafloor hydrothermal deposits. The area has lava flows that post-date the disappearance of the sea. The researchers cite these as evidence that this is an area of Mars' crust with a volcanic susceptibility that also could have produced effects earlier, when the sea was present. The new work adds to the diversity of types of wet environments for which evidence exists on Mars, including rivers, lakes, deltas, seas, hot springs, groundwater, and volcanic eruptions beneath ice. "Ancient, deep-water hydrothermal deposits in Eridania basin represent a new category of astrobiological target on Mars," the report states. It also says, "Eridania seafloor deposits are not only of interest for Mars exploration, they represent a window into early Earth." That is because the earliest evidence of life on Earth comes from seafloor deposits of similar origin and age, but the geological record of those early-Earth environments is poorly preserved. The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, built and
[meteorite-list] Examining Mars' Moon Phobos in a Different Light
https://www.jpl.nasa.gov/news/news.php?feature=6965 Examining Mars' Moon Phobos in a Different Light Jet Propulsion Laboratory October 4, 2017 NASA's longest-lived mission to Mars has gained its first look at the Martian moon Phobos, pursuing a deeper understanding by examining it in infrared wavelengths. The Thermal Emission Imaging System (THEMIS) camera on NASA's Mars Odyssey orbiter observed Phobos on Sept. 29, 2017. Researchers have combined visible-wavelength and infrared data to produce an image color-coded for surface temperatures of this moon, which has been considered for a potential future human-mission outpost. "Part of the observed face of Phobos was in pre-dawn darkness, part in morning daylight," said THEMIS Deputy Principal Investigator Victoria Hamilton of the Southwest Research Institute, headquartered in San Antonio. Looking across the image from left to right presents a sequence of times of day on the Martian moon, from before dawn, to sunrise, to increasing amounts of time after dawn. This provides information about how quickly the ground warms, which is related to the texture of the surface. As barefoot beach walks can confirm, sand warms or cools quicker than rocks or pavement. "Including a predawn area in the observation is useful because all the heating from the previous day's sunshine has reached its minimum there," Hamilton said. "As you go from predawn area to morning area you get to watch the heating behavior. If it heats up very quickly, it's likely not very rocky but dusty instead." Phobos has an oblong shape with an average diameter of about 14 miles (22 kilometers). Cameras on other Mars orbiters have previously taken higher-resolution images of Phobos, but none with the infrared information available from THEMIS. Observations in multiple bands of thermal-infrared wavelengths can yield information about the mineral composition of the surface, as well as the surface texture. One major question about Phobos and Mars' even smaller moon, Deimos, is whether they are captured asteroids or bits of Mars knocked into the sky by impacts. Compositional information from THEMIS might help pin down their origin. Since Odyssey began orbiting the Red Planet in 2001, THEMIS has provided compositional and thermal-properties information from all over Mars, but never before imaged either Martian moon. The Sept. 29 observation was completed to validate that the spacecraft could safely do so, as the start of a possible series of observations of Phobos and Deimos in coming months. In normal operating mode, Odyssey keeps the THEMIS camera pointed straight down as the spacecraft orbits Mars. In 2014, the spacecraft team at Lockheed Martin Space Systems, Denver; and NASA's Jet Propulsion Laboratory, Pasadena, California; and the THEMIS team at Arizona State University, Tempe, developed procedures to rotate the spacecraft for upward-looking imaging of a comet passing near Mars. The teams have adapted those procedures for imaging the Martian moons. "We now have the capability of rotating the spacecraft for THEMIS observations," said Odyssey Project Scientist Jeffrey Plaut of JPL. "There is heightened interest in Phobos because of the possibility that future astronauts could perhaps use it as an outpost." With the first observation now in hand, plans are advancing for additional opportunities at different illumination phases of Phobos and Deimos. "We want to get observations under all types of lighting -- fully daylit, a small crescent, during eclipse," Hamilton said. "We hope this is the first of several observations that will help us understand Phobos and Deimos." News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Karin Valentine / Robert Burnham Arizona State University, Tempe 480-965-9345 / 480-458-8207 karin.valent...@asu.edu / rburn...@mars.asu.edu Deb Schmid Southwest Research Institute, San Antonio 210-522-2254 deb.sch...@swri.org Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-260 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Glenn Tests Thruster Bound for Metal World
https://www.jpl.nasa.gov/news/news.php?feature=6958 NASA Glenn Tests Thruster Bound for Metal World Jet Propulsion Laboratory September 28, 2017 As NASA looks to explore deeper into our solar system, one of the key areas of interest is studying worlds that can help researchers better understand our solar system and the universe around us. One of the next destinations in this knowledge-gathering campaign is a rare world called Psyche, located in the asteroid belt. Psyche is different from millions of other asteroids because it appears to have an exposed nickel-iron surface. Researchers at Arizona State University, Tempe, in partnership with NASA's Jet Propulsion Laboratory in Pasadena, California, believe the asteroid could actually be the leftover core of an early planet. And, since we can't directly explore any planet's core, including our own, Psyche offers a rare look into the violent history of our solar system. "Psyche is a unique body because it is, by far, the largest metal asteroid out there; it's about the size of Massachusetts," said David Oh, the mission's lead project systems engineer at JPL. "By exploring Psyche, we'll learn about the formation of the planets, how planetary cores are formed and, just as important, we'll be exploring a new type of world. We've looked at worlds made of rock, ice and of gas, but we've never had an opportunity to look at a metal world, so this is brand new exploration in the classic style of NASA." But getting to Psyche won't be easy. It requires a cutting-edge propulsion system with exceptional performance, which is also safe, reliable and cost-effective. That's why the mission team has turned to NASA Glenn Research Center in Cleveland, which has been advancing solar electric propulsion (SEP) for decades. SEP thrusters use inert gases, like xenon, which are then energized by the electric power generated from onboard solar arrays to provide gentle, non-stop thrust. "For deep space missions, the type and amount of fuel required to propel a spacecraft is an important factor for mission planners," said Carol Tolbert, project manager for Psyche thruster testing at NASA Glenn. "A SEP system, like the one used for this mission, operates more efficiently than a conventional chemical propulsion system, which would be impractical for this type of mission." The reduced fuel mass allows the mission to enter orbit around Psyche and provides additional space for all of the mission's scientific payload. Psyche's payload includes a multispectral imager, magnetometer, and gamma-ray spectrometer. These instruments will help the science team better understand the asteroid's origin, composition and history. Additional benefits of SEP are flexibility and robustness in the flight plan, which allow the spacecraft to arrive at Psyche much faster and more efficiently than it could using conventional propulsion. For this mission, the spacecraft, which will be built jointly by JPL and Space Systems Loral (SSL), will use the SPT-140 Hall effect thruster. Because Psyche is three times farther away from the Sun than Earth, flying there required a unique test of the low-power operation of the thruster in the very low pressures that will be encountered in space. The mission team called upon NASA Glenn, and its space power and propulsion expertise, to put the mission's thruster through its paces at the center's Electric Propulsion Laboratory. "This mission will be the first to use a Hall effect thruster system beyond lunar orbit, so the tests here at Glenn, which had never been conducted before, were needed to ensure the thruster could perform and operate as expected in the deep space environment," said Tolbert. The facility at NASA Glenn has been a premier destination for electric propulsion and power system testing for over 40 years and features a number of space environment chambers, which simulate the vacuum and temperatures of space. "This was very important to the mission because we want to test-like-we-fly and fly-like-we-test," said Oh. "Glenn has a world-class facility that allowed us to go to very low pressures to simulate the environment the spacecraft will operate in and better understand how our thrusters will perform around Psyche. "At first glance, the results confirm our predictions regarding how the thruster will perform, and it looks like everything is working as expected. But, we will continue to refine our models by doing more analysis." As the team works toward an anticipated August 2022 launch, they will use the data collected at NASA Glenn to update their thruster modeling and incorporate it into mission trajectories. The scientific goals of the Psyche mission are to understand the building blocks of planet formation and explore firsthand a wholly new and unexplored type of world. The mission team seeks to determine whether Psyche is the core of an early planet, how old it is, whether it formed in
[meteorite-list] A Fresh Look at Older Data Yields a Surprise Near the Martian Equator
https://www.jpl.nasa.gov/news/news.php?feature=6956 A Fresh Look at Older Data Yields a Surprise Near the Martian Equator Jet Propulsion Laboratory September 28, 2017 Scientists taking a new look at older data from NASA's longest-operating Mars orbiter have discovered evidence of significant hydration near the Martian equator -- a mysterious signature in a region of the Red Planet where planetary scientists figure ice shouldn't exist. Jack Wilson, a post-doctoral researcher at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, led a team that reprocessed data collected from 2002 to 2009 by the neutron spectrometer instrument on NASA's Mars Odyssey spacecraft. In bringing the lower-resolution compositional data into sharper focus, the scientists spotted unexpectedly high amounts of hydrogen -- which at high latitudes is a sign of buried water ice -- around sections of the Martian equator. An accessible supply of water ice near the equator would be of interest in planning astronaut exploration of Mars. The amount of delivered mass needed for human exploration could be greatly reduced by using Martian natural resources for a water supply and as raw material for producing hydrogen fuel. By applying image-reconstruction techniques often used to reduce blurring and remove "noise" from medical or spacecraft imaging data, Wilson's team improved the spatial resolution of the data from around 320 miles to 180 miles (520 kilometers to 290 kilometers). "It was as if we'd cut the spacecraft's orbital altitude in half," Wilson said, "and it gave us a much better view of what's happening on the surface." The neutron spectrometer can't directly detect water, but by measuring neutrons, it can help scientists calculate the abundance of hydrogen -- and infer the presence of water or other hydrogen-bearing substances. Mars Odyssey's first major discovery, in 2002, was abundant hydrogen just beneath the surface at high latitudes. In 2008, NASA's Phoenix Mars Lander confirmed that the hydrogen was in the form of water ice. But at lower latitudes on Mars, water ice is not thought to be thermodynamically stable at any depth. The traces of excess hydrogen that Odyssey's original data showed at lower latitudes were initially explained as hydrated minerals, which other spacecraft and instruments have since observed. Wilson's team concentrated on those equatorial areas, particularly with a 600-mile (1,000-kilometer) stretch of loose, easily erodible material between the northern lowlands and southern highlands along the Medusae Fossae Formation. Radar-sounding scans of the area have suggested the presence of low-density volcanic deposits or water ice below the surface, "but if the detected hydrogen were buried ice within the top meter of the surface, there would be more than would fit into pore space in soil," Wilson said. The radar data came from both the Shallow Radar on NASA's Mars Reconnaissance Orbiter and the Mars Advanced Radar for Subsurface and Ionospheric Sounding on the European Space Agency's Mars Express orbiter and would be consistent with no subsurface water ice near the equator. How water ice could be preserved there is a mystery. A leading theory suggests an ice and dust mixture from the polar areas could be cycled through the atmosphere when Mars' axial tilt was larger than it is today. But those conditions last occurred hundreds of thousands to millions of years ago. Water ice isn't expected to be stable at any depth in that area today, Wilson said, and any ice deposited there should be long gone. Additional protection might come from a cover of dust and a hardened "duricrust" that traps the humidity below the surface, but this is unlikely to prevent ice loss over timescales of the axial tilt cycles. "Perhaps the signature could be explained in terms of extensive deposits of hydrated salts, but how these hydrated salts came to be in the formation is also difficult to explain," Wilson added. "So for now, the signature remains a mystery worthy of further study, and Mars continues to surprise us." Wilson led the research while at Durham University in the U.K. His team - which includes members from NASA Ames Research Center, the Planetary Science Institute and the Research Institute in Astrophysics and Planetology - published its findings this summer in the journal Icarus. News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Michael Buckley Johns Hopkins Applied Physics Laboratory, Laurel, Md. 240-228-7536 michael.buck...@jhuapl.edu Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-251 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com
[meteorite-list] NASA's Curiosity Mars Rover Climbing Toward Ridge Top
https://www.jpl.nasa.gov/news/news.php?feature=6946 NASA's Curiosity Mars Rover Climbing Toward Ridge Top Jet Propulsion Laboratory September 13, 2017 NASA's Mars rover Curiosity has begun the steep ascent of an iron-oxide-bearing ridge that's grabbed scientists' attention since before the car-sized rover's 2012 landing. "We're on the climb now, driving up a route where we can access the layers we've studied from below," said Abigail Fraeman, a Curiosity science-team member at NASA's Jet Propulsion Laboratory in Pasadena, California. "Vera Rubin Ridge" stands prominently on the northwestern flank of Mount Sharp, resisting erosion better than the less-steep portions of the mountain below and above it. The ridge, also called "Hematite Ridge," was informally named earlier this year in honor of pioneering astrophysicist Vera Rubin. "As we skirted around the base of the ridge this summer, we had the opportunity to observe the large vertical exposure of rock layers that make up the bottom part of the ridge," said Fraeman, who organized the rover's ridge campaign. "But even though steep cliffs are great for exposing the stratifications, they're not so good for driving up." The ascent to the top of the ridge from a transition in rock-layer appearance at the bottom of it will gain about 213 feet (65 meters) of elevation -- about 20 stories. The climb requires a series of drives totaling a little more than a third of a mile (570 meters). Before starting this ascent in early September, Curiosity had gained a total of about 980 feet (about 300 meters) in elevation in drives totaling 10.76 miles (17.32 kilometers) from its landing site to the base of the ridge. Curiosity's telephoto observations of the ridge from just beneath it show finer layering, with extensive bright veins of varying widths cutting through the layers. "Now we'll have a chance to examine the layers up close as the rover climbs," Fraeman said. Curiosity Project Scientist Ashwin Vasavada of JPL said, "Using data from orbiters and our own approach imaging, the team has chosen places to pause for more extensive studies on the way up, such as where the rock layers show changes in appearance or composition. But the campaign plan will evolve as we examine the rocks in detail. As always, it's a mix of planning and discovery." In orbital spectrometer observations, the iron-oxide mineral hematite shows up more strongly at the ridge top than elsewhere on lower Mount Sharp, including locations where Curiosity has already found hematite. Researchers seek to gain better understanding about why the ridge resists erosion, what concentrated its hematite, whether those factors are related, and what the rocks of the ridge can reveal about ancient Martian environmental conditions. "The team is excited to be exploring Vera Rubin Ridge, as this hematite ridge has been a go-to target for Curiosity ever since Gale Crater was selected as the landing site," said Michael Meyer, lead scientist of NASA's Mars Exploration Program at the agency's Washington headquarters. During the first year after its landing near the base of Mount Sharp, the Curiosity mission accomplished a major goal by determining that billions of years ago, a Martian lake offered conditions that would have been favorable for microbial life. Curiosity has since traversed through a diversity of environments where both water and wind have left their imprint. Vera Rubin Ridge and layers above it that contain clay and sulfate minerals provide tempting opportunities to learn even more about the history and habitability of ancient Mars. For more about Curiosity, visit: https://mars.jpl.nasa.gov/msl News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-241 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Mission Celebrates 10 Years in Space
https://www.jpl.nasa.gov/news/news.php?feature=6955 Dawn Mission Celebrates 10 Years in Space Jet Propulsion Laboratory September 27, 2017 Ten years ago, NASA's Dawn spacecraft set sail for the two most massive bodies in the asteroid belt between Mars and Jupiter: giant asteroid Vesta and dwarf planet Ceres. The mission was designed to deliver new knowledge about these small but intricate worlds, which hold clues to the formation of planets in our solar system. "Our interplanetary spaceship has exceeded all expectations in the last decade, delivering amazing insights about these two fascinating bodies," said Chris Russell, principal investigator of the Dawn mission, based at the University of California, Los Angeles. Since its launch on Sept. 27, 2007, Dawn has achieved numerous technical and scientific feats while traveling 4 billion miles (6 billion kilometers). It is the only spacecraft to orbit two extraterrestrial solar system targets. It is also the only spacecraft to orbit a dwarf planet, a milestone it achieved when in entered orbit around Ceres on March 6, 2015. The spacecraft's ion propulsion system enabled Dawn to study each of these worlds from a variety of vantage points and altitudes, creating an impressive scrapbook of 88,000 photos. Additionally, Dawn's suite of instruments enabled it to take a variety of other measurements of Vesta and Ceres, revealing the contrasting compositions and internal structures of these two bodies. Vesta Highlights Scientists learned a great deal about Vesta's geological features and composition during Dawn's 14 months of exploration there. A notable discovery was that Rheasilvia, a giant basin in Vesta's southern hemisphere, was even deeper and wider than scientists expected based on telescopic observations from Earth. It spans more than 310 miles (500 kilometers) and pierces about 12 miles (19 kilometers) into Vesta. The center of the crater also hosts a mountain twice the height of Mt. Everest -- the tallest feature seen in Dawn's 1,298 orbits of Vesta. The massive punch into Vesta that carved out this crater happened about 1 billion years ago and caused huge amounts of material to rain down on the surface. The net result is that the surface of the southern hemisphere of Vesta is younger than the northern hemisphere, which retains a hefty record of craters. The Rheasilvia impact also created dozens of gorges circling Vesta's equator. Canyons there, some of which formed from an earlier impact, measure up to 290 miles (465 kilometers) in length. Ceres Highlights One of Dawn's biggest revelations at Ceres is the extremely bright, salty material in Occator Crater that gleams amid an otherwise dark area. What appeared to be a single white blob at a distance turned out to be a smattering of many bright areas called faculae. The central bright area, Cerealia Facula, has a dome at its center with radial fractures across it that appears reddish in enhanced color images. This "bright spot" suggests Ceres was geologically active in the very recent past, when briny water rose to the surface and deposited salts. Just to the east are the Vinalia Faculae, a constellation of less-bright spots distributed along fractures that also intrigue scientists. Ceres hosts more than 300 small bright areas, with some thought to host ice at northern latitudes. Another huge surprise at Ceres was Ahuna Mons, which scientists believe formed as a cryovolcano, a volcano that erupted with salty water in the past. This "lonely mountain," 3 miles (5 kilometers) high on its steepest side, is unlike anything else on Ceres and remains a thriving research topic. Though both Ahuna Mons and Occator appear dormant, they suggest that liquid water flowed once beneath the surface of Ceres, and may even still be there today, if it is enriched in salts that would lower its freezing point. Dawn Science Continues "The science team is still actively exploring the troves of data that Dawn has delivered so far, comparing these two fossils of the early solar system," said Carol Raymond, Dawn deputy principal investigator, based at NASA's Jet Propulsion Laboratory, Pasadena, California. Since March 2015, Dawn has orbited Ceres 1,595 times. It remains healthy, currently in a 30-day elliptical orbit collecting data on cosmic rays in the vicinity of Ceres. "This continues to be a mission for everyone who yearns for new knowledge, everyone who is curious about the cosmos, and everyone who is exhilarated by bold adventures into the unknown," said Marc Rayman, mission director and chief engineer, based at JPL. Dawn's mission is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia,
[meteorite-list] NASA's Next Mars Mission to Investigate Interior of Red Planet (InSight)
https://www.jpl.nasa.gov/news/news.php?feature=6934 NASA's Next Mars Mission to Investigate Interior of Red Planet Jet Propulsion Laboratory August 28, 2017 Preparation of NASA's next spacecraft to Mars, InSight, has ramped up this summer, on course for launch next May from Vandenberg Air Force Base in central California -- the first interplanetary launch in history from America's West Coast. Lockheed Martin Space Systems is assembling and testing the InSight spacecraft in a clean room facility near Denver. "Our team resumed system-level integration and test activities last month," said Stu Spath, spacecraft program manager at Lockheed Martin. "The lander is completed and instruments have been integrated onto it so that we can complete the final spacecraft testing including acoustics, instrument deployments and thermal balance tests." InSight is the first mission to focus on examining the deep interior of Mars. Information gathered will boost understanding of how all rocky planets formed, including Earth. "Because the interior of Mars has churned much less than Earth's in the past three billion years, Mars likely preserves evidence about rocky planets' infancy better than our home planet does," said InSight Principal Investigator Bruce Banerdt of NASA's Jet Propulsion Laboratory, Pasadena, California. He leads the international team that proposed the mission and won NASA selection in a competition with 27 other proposals for missions throughout the solar system. The long form of InSight's name is Interior Exploration using Seismic Investigations, Geodesy and Heat Transport. Whichever day the mission launches during a five-week period beginning May 5, 2018, navigators have charted the flight to reach Mars the Monday after Thanksgiving in 2018. The mission will place a stationary lander near Mars' equator. With two solar panels that unfold like paper fans, the lander spans about 20 feet (6 meters). Within weeks after the landing -- always a dramatic challenge on Mars -- InSight will use a robotic arm to place its two main instruments directly and permanently onto the Martian ground, an unprecedented set of activities on Mars. These two instruments are: -- A seismometer, supplied by France's space agency, CNES, with collaboration from the United States, the United Kingdom, Switzerland and Germany. Shielded from wind and with sensitivity fine enough to detect ground movements half the diameter of a hydrogen atom, it will record seismic waves from "marsquakes" or meteor impacts that reveal information about the planet's interior layers. -- A heat probe, designed to hammer itself to a depth of 10 feet (3 meters) or more and measure the amount of energy coming from the planet's deep interior. The heat probe is supplied by the German Aerospace Center, DLR, with the self-hammering mechanism from Poland. A third experiment will use radio transmissions between Mars and Earth to assess perturbations in how Mars rotates on its axis, which are clues about the size of the planet's core. The spacecraft's science payload also is on track for next year's launch. The mission's launch was originally planned for March 2016, but was called off due to a leak into a metal container designed to maintain near-vacuum conditions around the seismometer's main sensors. A redesigned vacuum vessel for the instrument has been built and tested, then combined with the instrument's other components and tested again. The full seismometer instrument was delivered to the Lockheed Martin spacecraft assembly facility in Colorado in July and has been installed on the lander. "We have fixed the problem we had two years ago, and we are eagerly preparing for launch," said InSight Project Manager Tom Hoffman, of JPL. The best planetary geometry for launches to Mars occurs during opportunities about 26 months apart and lasting only a few weeks. JPL, a division of Caltech in Pasadena, California, manages the InSight Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the spacecraft. InSight is part of NASA's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. Together with two active NASA Mars rovers, three NASA Mars orbiters and a Mars rover being built for launch in 2020, InSight is part of a legacy of robotic exploration that is helping to lay the groundwork for sending humans to Mars in the 2030s. More information about InSight is online at: https://www.nasa.gov/insight https://insight.jpl.nasa.gov/ News Media Contact Guy Webster / Andrew Good Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 / 818-393-2433 guy.webs...@jpl.nasa.gov / andrew.c.g...@jpl.nasa.gov Danielle Hauf Lockheed Martin Space Systems Co., Denver 303-932-4360 danielle.m.h...@lmco.com Shannon Ridinger Marshall Space Flight Center, Huntsville, Ala. 256-544-3774 shannon.j.ridin...@nasa.gov Dwayne Brown /
[meteorite-list] Radar Reveals Two Moons Orbiting Asteroid Florence
https://cneos.jpl.nasa.gov/news/news199.html Radar Reveals Two Moons Orbiting Asteroid Florence Lance Benner, Shantanu Naidu, Marina Brozovic, and Paul Chodas Center for NEO Studies (CNEOS) September 1, 2017 Radar images of asteroid 3122 Florence obtained at the 70-meter antenna at NASA\u2019s Goldstone Deep Space Communications Complex between August 29 and September 1 have revealed that the asteroid has two small moons, and also confirmed that main asteroid Florence is about 4.5 km (2.8 miles) in size. Florence is only the third triple asteroid known in the near-Earth population out of more than 16,400 that have been discovered to date. All three near-Earth asteroid triples have been discovered with radar observations and Florence is the first seen since two moons were discovered around asteroid 1994 CC in June 2009. The sizes of the two moons are not yet well known, but they are probably between 100 - 300 meters (300-1000 feet) across. The times required for each moon to revolve around Florence are also not yet known precisely but appear to be roughly 8 hours for the inner moon and 22 to 27 hours for the outer moon. The inner moon of the Florence system has the shortest orbital period of any of the moons of the 60 near-Earth asteroids known to have moons. In the Goldstone radar images, which have a resolution of 75 meters, the moons are only a few pixels in extent and do not reveal any detail. Animated sequence of radar images of asteroid Florence obtained on Sep. 1, 2017 using the 70-m antenna at the Goldstone Deep Space Communications complex. The resolution of these images is about 75 meters. The images show two moons orbiting the much larger central body, which is about 4.5 km in diameter. The inner moon briefly disappears as it moves behind the central body and is hidden from the radar. (NASA/JPL). Animated sequence of radar images of asteroid Florence obtained on Sep. 1, 2017 using the 70-m antenna at the Goldstone Deep Space Communications complex. The resolution of these images is about 75 meters. The images show two moons orbiting the much larger central body, which is about 4.5 km in diameter. The inner moon briefly disappears as it moves behind the central body and is hidden from the radar. (NASA/JPL). The radar images also provide our first close-up view of Florence itself. Although the asteroid is fairly round, it has a ridge along its equator, at least one large crater, two large flat regions, and numerous other small-scale topographic features. The images also confirm that Florence rotates once every 2.4 hours, a result that was determined previously from optical measurements of the asteroid\u2019s brightness variations. [Animation] The animated sequence to the left is built from a series of radar images of Florence. The sequence lasts several hours and shows more than two full rotations of the large, primary body. The moons can be clearly seen as they orbit the main body. Radar images are different from pictures taken with a digital camera but are similar to ultrasound images. The geometry in radar images is analogous to seeing an object from above its north pole with the illumination coming from the top. Projection effects can make the positions of Florence and its moons appear to overlap even though they are not touching. Florence reached its closest approach to Earth early on September 1 and is now slowly receding from our planet. Additional radar observations are scheduled at NASA\u2019s Goldstone Solar System Radar in California and at the National Science Foundation\u2019s Arecibo Observatory in Puerto Rico through September 8. These observations should show more surface detail on Florence and provide more precise estimates of the orbital periods of the two moons. Those results are valuable to scientists because they can be used to estimate the total mass and density of the asteroid. __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Large, Distant Comets More Common Than Previously Thought
https://www.jpl.nasa.gov/news/news.php?feature=6902 Large, Distant Comets More Common Than Previously Thought Jet Propulsion Laboratory July 25, 2017 Comets that take more than 200 years to make one revolution around the Sun are notoriously difficult to study. Because they spend most of their time far from our area of the solar system, many "long-period comets" will never approach the Sun in a person's lifetime. In fact, those that travel inward from the Oort Cloud -- a group of icy bodies beginning roughly 186 billion miles (300 billion kilometers) away from the Sun -- can have periods of thousands or even millions of years. NASA's WISE spacecraft, scanning the entire sky at infrared wavelengths, has delivered new insights about these distant wanderers. Scientists found that there are about seven times more long-period comets measuring at least 0.6 miles (1 kilometer) across than had been predicted previously. They also found that long-period comets are on average up to twice as large as "Jupiter family comets," whose orbits are shaped by Jupiter's gravity and have periods of less than 20 years. Researchers also observed that in eight months, three to five times as many long-period comets passed by the Sun than had been predicted. The findings are published in the Astronomical Journal. "The number of comets speaks to the amount of material left over from the solar system's formation," said James Bauer, lead author of the study and now a research professor at the University of Maryland, College Park. "We now know that there are more relatively large chunks of ancient material coming from the Oort Cloud than we thought." The Oort Cloud is too distant to be seen by current telescopes, but is thought to be a spherical distribution of small icy bodies at the outermost edge of the solar system. The density of comets within it is low, so the odds of comets colliding within it are rare. Long-period comets that WISE observed probably got kicked out of the Oort Cloud millions of years ago. The observations were carried out during the spacecraft's primary mission before it was renamed NEOWISE and reactivated to target near-Earth objects (NEOs). "Our study is a rare look at objects perturbed out of the Oort Cloud," said Amy Mainzer, study co-author based at NASA's Jet Propulsion Laboratory, Pasadena, California, and principal investigator of the NEOWISE mission. "They are the most pristine examples of what the solar system was like when it formed." Astronomers already had broader estimates of how many long-period and Jupiter family comets are in our solar system, but had no good way of measuring the sizes of long-period comets. That is because a comet has a "coma," a cloud of gas and dust that appears hazy in images and obscures the cometary nucleus. But by using the WISE data showing the infrared glow of this coma, scientists were able to "subtract" the coma from the overall comet and estimate the nucleus sizes of these comets. The data came from 2010 WISE observations of 95 Jupiter family comets and 56 long-period comets. The results reinforce the idea that comets that pass by the Sun more often tend to be smaller than those spending much more time away from the Sun. That is because Jupiter family comets get more heat exposure, which causes volatile substances like water to sublimate and drag away other material from the comet's surface as well. "Our results mean there's an evolutionary difference between Jupiter family and long-period comets," Bauer said. The existence of so many more long-period comets than predicted suggests that more of them have likely impacted planets, delivering icy materials from the outer reaches of the solar system. Researchers also found clustering in the orbits of the long-period comets they studied, suggesting there could have been larger bodies that broke apart to form these groups. The results will be important for assessing the likelihood of comets impacting our solar system's planets, including Earth. "Comets travel much faster than asteroids, and some of them are very big," Mainzer said. "Studies like this will help us define what kind of hazard long-period comets may pose." NASA's Jet Propulsion Laboratory in Pasadena, California, managed and operated WISE for NASA's Science Mission Directorate in Washington. The NEOWISE project is funded by the Near Earth Object Observation Program, now part of NASA's Planetary Defense Coordination Office. The spacecraft was put into hibernation mode in 2011 after twice scanning the entire sky, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects. For more information on WISE, visit: https://www.nasa.gov/wise News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6425
[meteorite-list] Holographic Imaging Could Be Used to Detect Signs of Life in Space
https://www.caltech.edu/news/holographic-imaging-could-be-used-detect-signs-life-space-78931 Holographic Imaging Could Be Used to Detect Signs of Life in Space Engineers explore ways to sample and identify living microbes in the outer solar system Caltech July 20, 2017 We may be capable of finding microbes in space - but if we did, could we tell what they were, and that they were alive? This month the journal Astrobiology is publishing a special issue dedicated to the search for signs of life on Saturn's icy moon Enceladus. Included is a paper from Caltech's Jay Nadeau and colleagues offering evidence that a technique called digital holographic microscopy, which uses lasers to record 3-D images, may be our best bet for spotting extraterrestrial microbes. No probe since NASA's Viking program in the late 1970s has explicitly searched for extraterrestrial life - that is, for actual living organisms. Rather, the focus has been on finding water. Enceladus has a lot of water - an ocean's worth, hidden beneath an icy shell that coats the entire surface. But even if life does exist there in some microbial fashion, the difficulty for scientists on Earth is identifying those microbes from 790 million miles away. "It's harder to distinguish between a microbe and a speck of dust than you'd think," says Nadeau, research professor of medical engineering and aerospace in the Division of Engineering and Applied Science. "You have to differentiate between Brownian motion, which is the random motion of matter, and the intentional, self-directed motion of a living organism." Enceladus is the sixth-largest moon of Saturn, and is 100,000 times less massive than Earth. As such, Enceladus has an escape velocity - the minimum speed needed for an object on the moon to escape its surface - of just 239 meters per second. That is a fraction of Earth's, which is a little over 11,000 meters per second. Enceladus's minuscule escape velocity allows for an unusual phenomenon: enormous geysers, venting water vapor through cracks in the moon's icy shell, regularly jet out into space. When the Saturn probe Cassini flew by Enceladus in 2005, it spotted water vapor plumes in the south polar region blasting icy particles at nearly 2,000 kilometers per hour to an altitude of nearly 500 kilometers above the surface. Scientists calculated that as much as 250 kilograms of water vapor were released every second in each plume. Since those first observations, more than a hundred geysers have been spotted. This water is thought to replenish Saturn's diaphanous E ring, which would otherwise dissipate quickly, and was the subject of a recent announcement by NASA describing Enceladus as an "ocean world" that is the closest NASA has come to finding a place with the necessary ingredients for habitability. Water blasting out into space offers a rare opportunity, says Nadeau. While landing on a foreign body is difficult and costly, a cheaper and easier option might be to send a probe to Enceladus and pass it through the jets, where it would collect water samples that could possibly contain microbes. Assuming a probe were to do so, it would open up a few questions for engineers like Nadeau, who studies microbes in extreme environments. Could microbes survive a journey in one of those jets? If so, how could a probe collect samples without destroying those microbes? And if samples are collected, how could they be identified as living cells? The problem with searching for microbes in a sample of water is that they can be difficult to identify. "The hardest thing about bacteria is that they just don't have a lot of cellular features," Nadeau says. Bacteria are usually blob-shaped and always tiny - smaller in diameter than a strand of hair. "Sometimes telling the difference between them and sand grains is very difficult," Nadeau says. Some strategies for demonstrating that a microscopic speck is actually a living microbe involve searching for patterns in its structure or studying its specific chemical composition. While these methods are useful, they should be used in conjunction with direct observations of potential microbes, Nadeau says. "Looking at patterns and chemistry is useful, but I think we need to take a step back and look for more general characteristics of living things, like the presence of motion. That is, if you see an E. coli, you know that it is alive - and not, say, a grain of sand - because of the way it is moving," she says. In earlier work, Nadeau suggested that the movement exhibited by many living organisms could potentially be used as a robust, chemistry-independent biosignature for extraterrestrial life. The motion of living organisms can also be triggered or enhanced by "feeding" the microbes electrons and watching them grow more active. To study the motion of potential microbes from Enceladus's plumes, Nadeau proposes using an instrument called a digital
[meteorite-list] From Mars Rover Opportunity: Panorama Above 'Perseverance Valley'
https://www.jpl.nasa.gov/news/news.php?feature=6898 >From Mars Rover: Panorama Above 'Perseverance Valley' Jet Propulsion Laboratory July 20, 2017 NASA's Mars Exploration Rover Opportunity recorded a panoramic view before entering the upper end of a fluid-carved valley that descends the inner slope of a large crater's rim. The scene includes a broad notch in the crest of the crater's rim, which may have been a spillway where water or ice or wind flowed over the rim and into the crater. Wheel tracks visible in the area of the notch were left by Opportunity as the rover studied the ground there and took images into the valley below for use in planning its route. "It is a tantalizing scene," said Opportunity Deputy Principal Investigator Ray Arvidson of Washington University in St. Louis. "You can see what appear to be channels lined by boulders, and the putative spillway at the top of Perseverance Valley. We have not ruled out any of the possibilities of water, ice or wind being responsible." Opportunity's panoramic camera (Pancam) took the component images of the scene during a two-week driving moratorium in June 2017 while rover engineers diagnosed a temporary stall in the left-front wheel's steering actuator. The wheel was pointed outward more than 30 degrees, prompting the team to call the resulting vista Pancam's "Sprained Ankle" panorama. Both ends of the scene show portions of Endeavour Crater's western rim, extending north and south, and the center of the scene shows terrain just outside the crater. The team was able to straighten the wheel to point straight ahead, and now uses the steering capability of only the two rear wheels. The right-front wheel's steering actuator has been disabled since 2006. Opportunity has driven 27.95 miles (44.97 kilometers) since landing on Mars in 2004. On July 7, 2017, Opportunity drove to the site within upper Perseverance Valley where it will spend about three weeks without driving while Mars passes nearly behind the sun from Earth's perspective, affecting radio communications. The rover's current location is just out of sight in the Sprained Ankle panorama, below the possible spillway. Opportunity is using Pancam to record another grand view from this location. After full communications resume in early August, the team plans to drive Opportunity farther down Perseverance Valley, seeking to learn more about the process that carved it. For more information about Opportunity's adventures on Mars, visit: https://mars.nasa.gov/mer News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Large Asteroid 3122 Florence to Safely Pass Earth on Sept. 1
https://www.jpl.nasa.gov/news/news.php?feature=6927 Large Asteroid to Safely Pass Earth on Sept. 1 Jet Propulsion Laboratory August 17, 2017 Asteroid Florence, a large near-Earth asteroid, will pass safely by Earth on Sept. 1, 2017, at a distance of about 4.4 million miles, (7.0 million kilometers, or about 18 Earth-Moon distances). Florence is among the largest near-Earth asteroids that are several miles in size; measurements from NASA's Spitzer Space Telescope and NEOWISE mission indicate it's about 2.7 miles (4.4 kilometers) in size. "While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller," said Paul Chodas, manager of NASA's Center for Near-Earth Object Studies (CNEOS) at the agency's Jet Propulsion Laboratory in Pasadena, California. "Florence is the largest asteroid to pass by our planet this close since the NASA program to detect and track near-Earth asteroids began." This relatively close encounter provides an opportunity for scientists to study this asteroid up close. Florence is expected to be an excellent target for ground-based radar observations. Radar imaging is planned at NASA's Goldstone Solar System Radar in California and at the National Science Foundation's Arecibo Observatory in Puerto Rico. The resulting radar images will show the real size of Florence and also could reveal surface details as small as about 30 feet (10 meters). Asteroid Florence was discovered by Schelte "Bobby" Bus at Siding Spring Observatory in Australia in March 1981. It is named in honor of Florence Nightingale (1820-1910), the founder of modern nursing. The 2017 encounter is the closest by this asteroid since 1890 and the closest it will ever be until after 2500. Florence will brighten to ninth magnitude in late August and early September, when it will be visible in small telescopes for several nights as it moves through the constellations Piscis Austrinus, Capricornus, Aquarius and Delphinus. Radar has been used to observe hundreds of asteroids. When these small, natural remnants of the formation of the solar system pass relatively close to Earth, deep space radar is a powerful technique for studying their sizes, shapes, rotation, surface features and roughness, and for more precise determination of their orbital path. JPL manages and operates NASA's Deep Space Network, including the Goldstone Solar System Radar, and hosts the Center for Near-Earth Object Studies for NASA's Near-Earth Object Observations Program, an element of the Planetary Defense Coordination Office within the agency's Science Mission Directorate. More information about asteroids and near-Earth objects can be found at: https://cneos.jpl.nasa.gov https://www.jpl.nasa.gov/asteroidwatch For more information about NASA's Planetary Defense Coordination Office, visit: https://www.nasa.gov/planetarydefense For asteroid and comet news and updates, follow AsteroidWatch on Twitter: twitter.com/AsteroidWatch News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 a...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-223 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Curiosity Mars Rover Begins Study of Ridge Destination
https://www.jpl.nasa.gov/news/news.php?feature=6894 Curiosity Mars Rover Begins Study of Ridge Destination Jet Propulsion Laboratory July 11, 2017 The car-size NASA rover on a Martian mountain, Curiosity, has begun its long-anticipated study of an iron-bearing ridge forming a distinctive layer on the mountain's slope. Since before Curiosity's landing five years ago next month, this feature has been recognized as one of four unique terrains on lower Mount Sharp and therefore a key mission destination. Curiosity's science team informally named it "Vera Rubin Ridge" this year, commemorating astronomer Vera Cooper Rubin (1928-2016). "Our Vera Rubin Ridge campaign has begun," said Curiosity Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory, Pasadena, California. "Curiosity is driving parallel to the ridge, below it, observing it from different angles as we work our way toward a safe route to the top of the ridge." A major appeal of the ridge is an iron-oxide mineral, hematite, which can form under wet conditions and reveal information about ancient environments. Hematite-bearing rocks elsewhere on Mars were the scientific basis for choosing the 2004 landing site of an older and still-active rover, Opportunity. Studies of Mount Sharp with the Compact Reconnaissance Imaging Spectrometer for Mars, on NASA's Mars Reconnaissance Orbiter, identified hematite in the ridge and also mapped water-related clay and sulfate minerals in layers just above it. Vera Rubin Ridge stands about eight stories tall, with a trough behind it where clay minerals await. Curiosity is now near the downhill face, which forms an impressive wall for much of the ridge's length of about 4 miles (6.5 kilometers). "In this first phase of the campaign, we're studying the sedimentary structures in the wall," said JPL's Abigail Fraeman, a Curiosity science-team member who helped plan these observations. This summer's investigations also seek information about the boundary zone between the material that makes up the ridge and the geological unit that Curiosity has been studying since late 2014: the Murray formation of lower Mount Sharp, which holds evidence of ancient lakes. The Murray formation has variable levels of hematite, but whether the hematite in it and in the ridge accumulated under similar environmental conditions is unknown. The planned ascent route will provide access to closer inspection of the hematite-bearing rocks. "We want to determine the relationship between the conditions that produced the hematite and the conditions under which the rock layers of the ridge were deposited," Fraeman said. "Were they deposited by wind, or in a lake, or some other setting? Did the hematite form while the sediments accumulated, or later, from fluids moving through the rock?" Deciphering the history of the ridge's hematite may shed light on whether the freshwater environments that deposited the layers of the older Murray formation were turning more acidic by the time the layers of the ridge formed. The mission also will be watching for clues about whether a gradient in oxidation levels was present, as that could have provided a potential energy source for microbial life. Terrain near the base of the ridge is rife with boulders and sand, creating challenging conditions for navigation, as well as opportunities to add to the mission's studies of sand dunes and ripples. The largest sand dunes were at lower elevations, including a linear dune informally named "Nathan Bridges Dune" in memory of Nathan Bridges (1966-2017), a Curiosity team member who helped lead the mission's dune studies. During the first year after its landing on Aug. 5, 2012, PDT (Aug. 6, EDT and Universal Time), the Curiosity mission accomplished a major goal by determining that billions of years ago, a Martian lake offered conditions that would have been favorable for microbial life. Curiosity has since traversed through a diversity of environments where both water and wind have left their imprint. The upcoming exploration of Vera Rubin Ridge and the higher clay and sulfate layers provides opportunities to learn even more about the history and habitability of ancient Mars. For more about Curiosity, visit: https://mars.jpl.nasa.gov/msl Status of Curiosity's Drill The rover team will not have Curiosity's rock sampling drill available in the first phase of studying "Vera Rubin Ridge." The drill feed mechanism, which moves the bit forward or back, faulted on Dec. 1, 2016, and no rocks have been drilled since then. While continuing to test possible ways to move the bit with the drill feed mechanism, rover engineers are also now studying alternative ways to drill. For the 15 rocks that Curiosity has sampled with its drill so far, two stabilizer posts, one to each side of the bit, were placed against the rock before the bit was extended with the feed mechanism. "We are investigating methods to
[meteorite-list] The Day The Internet Stood Still
https://www.nasa.gov/specials/pathfinder20/ The Day The Internet Stood Still By Brian Dunbar July 2017 Twenty years ago, NASA landed a little rover on Mars . . . and blew up the Internet. As people clamored for pictures - overwhelming servers and bringing network traffic to a standstill - it became obvious that something fundamental had changed on how people expected to get information about NASA missions. NASA, through its Jet Propulsion Laboratory in California, had begun to release information online following Voyager's encounters with Uranus and Neptune in the 1980s. "When I arrived at JPL in 1985, I was already active in some of the online networks of the day such as CompuServe, so distributing pictures and information about NASA missions that way seemed natural," said former JPL public information manager Frank O'Donnell. "Also, Ron Baalke at JPL was very active posting information to Usenet, the Internet-based system of newsgroups. At the end of the '80s, I established a dialup bulletin board system at JPL, which members of the public could dial into directly to download pictures and text files." Then, in 1993, came the discovery of Comet Shoemaker-Levy 9, and astronomers' realization that it would hit Jupiter in July 1994. By then scientists were communicating by e-mail, transferring large files around the world and posting their work for discussion on the nascent World Wide Web. Now they were using those tools to plan worldwide campaign to observe the collision NASA's public affairs office followed suit, scheduling briefings throughout the encounter. (The comet had fragmented into numerous pieces that would arrive at Jupiter over several days.) The schedule published the time images were expected to be received and when they would be discussed on NASA TV. Naturally, Internet users started banging on NASA websites a few minutes before the pictures were scheduled to be downlinked, unable to wait until the scheduled release time. As Philip C. Plait wrote in "Bad Astronomy", ". . . the web nearly screeched to a halt due to the overwhelming amount of traffic as people tried to find pictures of the event from different observatories." The excitement wasn't limited to the public. Scientists found themselves doing their work live on NASA TV, as this clip from a National Geographic special shows. By coincidence it was also around this time that NASA's Office of Public Affairs announced that it would no longer mail news releases to reporters, but would instead distribute them online. Crowd-sourced Shoemaker-Levy made it clear to JPL they would have to prepare for something even bigger with Mars Pathfinder. Webmaster David Dubov told the New York Times shortly after the landing that he estimated the site would be receiving 25 million hits a day. (A "hit" is a request for information from one computer to another. On the web, a hit can represent the transfer of a picture, text or other page element. In the case of Pathfinder's deliberately stripped-down site, each web page comprised a few hits.) Dubov and JPL engineer Kirk Goodall would later revise that estimate to 60-80 million hits a day, traffic that would crash JPL's networks if the servers were hosted there. Goodall set out to build a network of mirror sites that could take the traffic off JPL's networks. Working with other U.S. science agencies, and ultimately corporations and Internet "backbone" providers, he did just that. (In other words, JPL crowd-sourced their solution a couple of decades before anyone knew crowdsourcing was a thing.) And the solution worked. The site took 30 million hits on landing day, July 4. On July 7, the first weekday after the landing, the site got 80 million hits. In comparison, the year before, the chess match between Gary Kasparov and IBM's Deep Blue computer peaked at 21 million hits, and the Atlanta Olympics website had topped out at 18 million hits on one day. Direct-to-Digital "One of the biggest changes with Mars Pathfinder was that it was the first mission that fully embraced the Internet as a primary way of getting out information to the public," said O'Donnell. "Before Pathfinder, the prevailing thinking was that eight-by-ten photo prints were the product needed for the public at large." It's worth remembering how the public got to see NASA images before the Internet era. NASA teams would review the raw images, select a few and distribute them as physical prints at news conferences. Media had to be in attendance at the conference to get a copy. Most newspapers and TV stations had to wait until a wire service had scanned the image and sent it out over their proprietary network. Most people might see a new image every day for a few days. A week later there might be a few more images published in weekly news magazines. Maybe six or eight months later, a ma
[meteorite-list] NASA Finds Evidence of Diverse Environments in Curiosity Samples
https://www.jpl.nasa.gov/news/news.php?feature=6870 NASA Finds Evidence of Diverse Environments in Curiosity Samples Jet Propulsion Laboratory June 9, 2017 NASA scientists have found a wide diversity of minerals in the initial samples of rocks collected by the Curiosity rover in the lowermost layers of Mount Sharp on Mars, suggesting that conditions changed in the water environments on the planet over time. Curiosity landed near Mount Sharp in Gale Crater in August 2012. It reached the base of the mountain in 2014. Layers of rocks at the base of Mount Sharp accumulated as sediment within ancient lakes around 3.5 billion years ago. Orbital infrared spectroscopy had shown that the mountain's lowermost layers have variations in minerals that suggest changes in the area have occurred. In a paper published recently in Earth and Planetary Science Letters, scientists in the Astromaterials Research and Exploration Science (ARES) Division at NASA's Johnson Space Center in Houston report on the first four samples collected from the lower layers of Mount Sharp. "We went to Gale Crater to investigate these lower layers of Mount Sharp that have these minerals that precipitated from water and suggest different environments," said Elizabeth Rampe, the first author of the study and a NASA exploration mission scientist at Johnson. "These layers were deposited about 3.5 billion years ago, coinciding with a time on Earth when life was beginning to take hold. We think early Mars may have been similar to early Earth, and so these environments might have been habitable." The minerals found in the four samples drilled near the base of Mount Sharp suggest several different environments were present in ancient Gale Crater. There is evidence for waters with different pH and variably oxidizing conditions. The minerals also show that there were multiple source regions for the rocks in "Pahrump Hills" and "Marias Pass." The paper primarily reports on three samples from the Pahrump Hills region. This is an outcrop at the base of Mount Sharp that contains sedimentary rocks scientists believe formed in the presence of water. The other sample, called "Buckskin," was reported last year, but those data are incorporated into the paper. Studying such rock layers can yield information about Mars' past habitability, and determining minerals found in the layers of sedimentary rock yields much data about the environment in which they formed. Data collected at Mount Sharp with the Chemistry and Mineralogy (CheMin) instrument on Curiosity showed a wide diversity of minerals. At the base are minerals from a primitive magma source; they are rich in iron and magnesium, similar to basalts in Hawaii. Moving higher in the section, scientists saw more silica-rich minerals. In the "Telegraph Peak" sample, scientists found minerals similar to quartz. In the "Buckskin" sample, scientists found tridymite. Tridymite is found on Earth, for example, in rocks that formed from partial melting of Earth's crust or in the continental crust -- a strange finding because Mars never had plate tectonics. In the "Confidence Hills" and "Mojave 2" samples, scientists found clay minerals, which generally form in the presence of liquid water with a near-neutral pH, and therefore could be good indicators of past environments that were conducive to life. The other mineral discovered here was jarosite, a salt that forms in acidic solutions. The jarosite finding indicates that there were acidic fluids at some point in time in this region. There are different iron-oxide minerals in the samples as well. Hematite was found near the base; only magnetite was found at the top. Hematite contains oxidized iron, whereas magnetite contains both oxidized and reduced forms of iron. The type of iron-oxide mineral present may tell scientists about the oxidation potential of the ancient waters. The authors discuss two hypotheses to explain this mineralogical diversity. The lake waters themselves at the base were oxidizing, so either there was more oxygen in the atmosphere or other factors encouraged oxidation. Another hypothesis -- the one put forward in the paper -- is that later-stage fluids arose. After the rock sediments were deposited, some acidic, oxidizing groundwater moved into the area, leading to precipitation of the jarosite and hematite. In this scenario, the environmental conditions present in the lake and in later groundwater were quite different, but both offered liquid water and a chemical diversity that could have been exploited by microbial life. "We have all this evidence that Mars was once really wet but now is dry and cold," Rampe said. "Today, much of the water is locked up in the poles and in the ground at high latitudes as ice. We think that the rocks Curiosity has studied reveal ancient environmental changes that occurred as Mars started to lose its atmosphere and water was lost to space." In the
[meteorite-list] NASA's Asteroid-Hunting Spacecraft a Discovery Machine (NEOWISE)
https://www.jpl.nasa.gov/news/news.php?feature=6864 NASA's Asteroid-Hunting Spacecraft a Discovery Machine Jet Propulsion Laboratory June 5, 2017 NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission has released its third year of survey data, with the spacecraft discovering 97 previously unknown celestial objects in the last year. Of those, 28 were near-Earth objects, 64 were main belt asteroids and five were comets. The spacecraft has now characterized a total of 693 near-Earth objects since the mission was re-started in December 2013. Of these, 114 are new. The NEOWISE team has released an animation depicting this solar system survey's discoveries and characterizations for its third year of operations. "NEOWISE is not only discovering previously uncharted asteroids and comets, but it is providing excellent data on many of those already in our catalog," said Amy Mainzer, NEOWISE principal investigator from NASA's Jet Propulsion Laboratory in Pasadena, California. "It is also proving to be an invaluable tool in in the refining and perfecting of techniques for near-Earth object discovery and characterization by a space-based infrared observatory." Near-Earth objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of the planets in our solar system into orbits that allow them to enter Earth's neighborhood. Ten of the objects discovered by NEOWISE in the past year have been classified as potentially hazardous asteroids, based on their size and their orbits. More than 2.6 million infrared images of the sky were collected in the third year of operations by NEOWISE. These data are combined with the Year 1 and 2 NEOWISE data into a single archive that contains approximately 7.7 million sets of images and a database of more than 57.7 billion source detections extracted from those images. The NEOWISE images also contain glimpses of rare objects, like comet C/2010 L5 WISE. A new technique of modeling comet behavior called tail-fitting showed that this particular comet experienced a brief outburst as it swept through the inner-solar system. "Comets that have abrupt outbursts are not commonly found, but this may be due more to the sudden nature of the activity rather than their inherent rarity," said Emily Kramer, a NASA Postdoctoral Program Fellow at JPL and lead author of paper on the NEOWISE study. "It is great for astronomers to view and collect cometary data when they find an outburst, but since the activity is so short-lived, we may simply miss them most of the time." The tail-fitting technique identifies the size and quantity of dust particles in the vicinity of the comet, and when they were ejected from the comet's nucleus, revealing the history of the comet's activity. With tail-fitting, future all-sky surveys may be able to find and collect data on more cometary outburst activity when it happens. A paper detailing the tail-fitting technique and other results of the study was published in the March 20 volume of the Astrophysical Journal. Originally called the Wide-field Infrared Survey Explorer (WISE), the spacecraft was launched in December 2009. It was placed in hibernation in 2011 after its primary astrophysics mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission: to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE also is characterizing more distant populations of asteroids and comets to provide information about their sizes and compositions. NASA's Jet Propulsion Laboratory in Pasadena, California, manages the NEOWISE mission for NASA's Planetary Defense Coordination Office within the Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at Caltech in Pasadena. Caltech manages JPL for NASA. To review the latest data release from NEOWISE please visit: http://wise2.ipac.caltech.edu/docs/release/neowise/ For more information about NEOWISE, visit: https://www.nasa.gov/neowise and http://neowise.ipac.caltech.edu/ More information about asteroids and near-Earth objects is at: https://www.jpl.nasa.gov/asteroidwatch News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 a...@jpl.nasa.gov Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2017-159 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com
[meteorite-list] Curiosity Peels Back Layers on Ancient Martian Lake
https://www.jpl.nasa.gov/news/news.php?feature=6863 Curiosity Peels Back Layers on Ancient Martian Lake Jet Propulsion Laboratory June 1, 2017 Fast Facts: o NASA's Curiosity Mars rover mission has provided an unprecedented level of detail about an ancient lake environment on Mars that offered favorable conditions for microbial life. o A lake in Mars' Gale Crater long ago was stratified, with oxidant-rich shallows and oxidant-poor depths. o The lake offered multiple types of microbe-friendly environments simultaneously. A long-lasting lake on ancient Mars provided stable environmental conditions that differed significantly from one part of the lake to another, according to a comprehensive look at findings from the first three-and-a-half years of NASA's Curiosity rover mission. Different conditions favorable for different types of microbes existed simultaneously in the same lake. Previous work had revealed the presence of a lake more than three billion years ago in Mars' Gale Crater. This study defines the chemical conditions that existed in the lake and uses Curiosity's powerful payload to determine that the lake was stratified. Stratified bodies of water exhibit sharp chemical or physical differences between deep water and shallow water. In Gale's lake, the shallow water was richer in oxidants than deeper water was. "These were very different, co-existing environments in the same lake," said Joel Hurowitz of Stony Brook University, Stony Brook, New York, lead author of a report of the findings in the June 2 edition of the journal Science. "This type of oxidant stratification is a common feature of lakes on Earth, and now we've found it on Mars. The diversity of environments in this Martian lake would have provided multiple opportunities for different types of microbes to survive, including those that thrive in oxidant-rich conditions, those that thrive in oxidant-poor conditions, and those that inhabit the interface between those settings." Whether Mars has ever hosted any life is still unknown, but seeking signs of life on any planet -- whether Earth, Mars or more-distant icy worlds -- begins with reconstruction of the environment to determine if it was capable of supporting life. Curiosity's primary goal when it landed inside Gale Crater in 2012 was to determine whether Mars has ever offered environmental conditions favorable for microbial life. In its first year, on the crater floor at "Yellowknife Bay," the rover found evidence of ancient freshwater river and lake environments with all the main chemical ingredients for life and a possible energy source for life. Curiosity has since driven to the base of Mount Sharp, a layered mountain inside the crater, and inspected rock layers that grow progressively younger as the rover gains elevation on lower Mount Sharp. Differences in the physical, chemical and mineral characteristics of several sites on lower Mount Sharp at first presented a puzzle to the rover team. For example, some rocks showed thicker layering with a larger proportion of an iron mineral called hematite, while other rocks showed very fine layers and more of an iron mineral called magnetite. Comparing these properties suggested very distinctive environments of deposition. Researchers considered whether these differences could have resulted from environmental conditions fluctuating over time or differing from place to place. "We could tell something was going on," Hurowitz said. "What was causing iron minerals to be one flavor in one part of the lake and another flavor in another part of the lake? We had an 'Aha!' moment when we realized that the mineral information and the bedding-thickness information mapped perfectly onto each other in a way you would expect from a stratified lake with a chemical boundary between shallow water and deeper water." In addition to revealing new information about chemical conditions within the lake, the report by Hurowitz and 22 co-authors also documents fluctuations in the climate of ancient Mars. One such change happened between the time crater-floor rocks were deposited and the time the rocks that now make up the base of Mount Sharp were deposited. Those later rocks are exposed at "Pahrump Hills" and elsewhere. The method the team used for detecting changes in ancient climate conditions on Mars resembles how ice cores are used to study past temperature conditions on Earth. It is based on comparing differences in the chemical composition of layers of mud-rich sedimentary rock that were deposited in quiet waters in the lake. While the lake was present in Gale, climate conditions changed from colder and drier to warmer and wetter. Such short-term fluctuations in climate took place within a longer-term climate evolution from the ancient warmer and wetter conditions that supported lakes, to today's arid Mars. "These results give us unprecedented detail in answering questions about
[meteorite-list] Cassini Finds Saturn Moon Enceladus May Have Tipped Over
https://www.jpl.nasa.gov/news/news.php?feature=6860 Cassini Finds Saturn Moon May Have Tipped Over Jet Propulsion Laboratory May 30, 2017 Saturn's icy, ocean-bearing moon Enceladus may have tipped over in the distant past, according to recent research from NASA's Cassini mission. Researchers with the mission found evidence that the moon's spin axis -- the line through the north and south poles -- has reoriented, possibly due to a collision with a smaller body, such as an asteroid. Examining the moon's features, the team showed that Enceladus appears to have tipped away from its original axis by about 55 degrees -- more than halfway toward rolling completely onto its side. "We found a chain of low areas, or basins, that trace a belt across the moon's surface that we believe are the fossil remnants of an earlier, previous equator and poles," said Radwan Tajeddine, a Cassini imaging team associate at Cornell University, Ithaca, New York, and lead author of the paper. The area around the icy moon's current south pole is a geologically active region where long, linear fractures referred to as tiger stripes slice across the surface. Tajeddine and colleagues speculate that an asteroid may have struck the region in the past when it was closer to the equator. "The geological activity in this terrain is unlikely to have been initiated by internal processes," he said. "We think that, in order to drive such a large reorientation of the moon, it's possible that an impact was behind the formation of this anomalous terrain." In 2005, Cassini discovered that jets of water vapor and icy particles spray from the tiger stripe fractures -- evidence that an underground ocean is venting directly into space from beneath the active south polar terrain. Whether it was caused by an impact or some other process, Tajeddine and colleagues think the disruption and creation of the tiger-stripe terrain caused some of Enceladus' mass to be redistributed, making the moon's rotation unsteady and wobbly. The rotation would have eventually stabilized, likely taking more than a million years. By the time the rotation settled down, the north-south axis would have reoriented to pass through different points on the surface -- a mechanism researchers call "true polar wander." The polar wander idea helps to explain why Enceladus' modern-day north and south poles appear quite different. The south is active and geologically young, while the north is covered in craters and appears much older. The moon's original poles would have looked more alike before the event that caused Enceladus to tip over and relocate the disrupted tiger-stripe terrain to the moon's south polar region. The results were published in the online edition of the journal Icarus on April 30, 2017. The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter. More information about Cassini: https://www.nasa.gov/cassini https://saturn.jpl.nasa.gov News Media Contact Preston Dyches Jet Propulsion Laboratory, Pasadena, Calif. 818-394-7013 preston.dyc...@jpl.nasa.gov 2017-155 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] High-Silica 'Halos' Shed Light on Wet Ancient Mars
https://www.jpl.nasa.gov/news/news.php?feature=6859 High-Silica 'Halos' Shed Light on Wet Ancient Mars Jet Propulsion Laboratory May 30, 2017 Pale "halos" around fractures in bedrock analyzed by NASA's Curiosity Mars rover contain copious silica, indicating that ancient Mars had liquid water for a long time. "The concentration of silica is very high at the centerlines of these halos," said Jens Frydenvang, a rover-team scientist at Los Alamos National Laboratory in New Mexico, and the University of Copenhagen in Denmark. "What we're seeing is that silica appears to have migrated between very old sedimentary bedrock and into younger overlying rocks." Frydenvang is the lead author of a report about these findings published in Geophysical Research Letters. NASA landed Curiosity on Mars in 2012 with a goal to determine whether Mars ever offered environmental conditions favorable for microbial life. The mission "has been very successful in showing that Gale Crater once held a lake with water that we would even have been able to drink from, but we still don't know how long this habitable environment endured," he said. "What this finding tells us is that, even when the lake eventually evaporated, substantial amounts of groundwater were present for longer than we previously thought -- further expanding the window for when life might have existed on Mars." For more information about the newly published report, visit: http://bit.ly/2r8dyOF The halos were first analyzed in 2015 with Curiosity's science-instrument payload, including the laser-shooting Chemistry and Camera (ChemCam) instrument, which was developed at Los Alamos National Laboratory in conjunction with the French space agency. The rover has subsequently explored higher and younger layers of lower Mount Sharp, investigating how ancient environmental conditions changed. NASA's two active Mars rovers and three Mars orbiters are all part of ambitious robotic exploration to understand Mars, which helps lead the way for sending humans to Mars in the 2030s. The Curiosity mission is managed by NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, for NASA's Science Mission Directorate, Washington. For more about Curiosity, visit: http://www.nasa.gov/curiosity News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Laura Mullane Los Alamos National Laboratory, Los Alamos, N.M. 505-667-6012 mull...@lanl.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-154 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Rover Opportunity Begins Study of Valley's Origin
https://www.jpl.nasa.gov/news/news.php?feature=6844 Mars Rover Opportunity Begins Study of Valley's Origin Jet Propulsion Laboratory May 15, 2017 NASA's Mars Exploration Rover Opportunity has reached the main destination of its current two-year extended mission -- an ancient fluid-carved valley incised on the inner slope of a vast crater's rim. As the rover approached the upper end of "Perseverance Valley" in early May, images from its cameras began showing parts of the area in greater resolution than what can be seen in images taken from orbit above Mars. "The science team is really jazzed at starting to see this area up close and looking for clues to help us distinguish among multiple hypotheses about how the valley formed," said Opportunity Project Scientist Matt Golombek of NASA's Jet Propulsion Laboratory, Pasadena, California. The process that carved Perseverance Valley into the rim of Endeavour Crater billions of years ago has not yet been identified. Among the possibilities: It might have been flowing water, or might have been a debris flow in which a small amount of water lubricated a turbulent mix of mud and boulders, or might have been an even drier process, such as wind erosion. The mission's main objective with Opportunity at this site is to assess which possibility is best supported by the evidence still in place. The upper end of the valley is at a broad notch in the crest of the crater rim. The rover team's plan for investigating the area begins with taking sets of images of the valley from two widely separated points at that dip in the rim. This long-baseline stereo imaging will provide information for extraordinarily detailed three-dimensional analysis of the terrain. The valley extends down from the rim's crest line into the crater, at a slope of about 15 to 17 degrees for a distance of about two football fields. "The long-baseline stereo imaging will be used to generate a digital elevation map that will help the team carefully evaluate possible driving routes down the valley before starting the descent," said Opportunity Project Manager John Callas of JPL. Reversing course back uphill when partway down could be difficult, so finding a path with minimum obstacles will be important for driving Opportunity through the whole valley. Researchers intend to use the rover to examine textures and compositions at the top, throughout the length and at the bottom, as part of investigating the valley's history. While the stereo imaging is being analyzed for drive-planning, the team plans to use the rover to examine the area immediately west of the crater rim at the top of the valley. "We expect to do a little walkabout just outside the crater before driving down Perseverance Valley," Golombek said. The mission has begun its 150th month since the early 2004 landing of Opportunity in the Meridiani Planum region of Mars. In the first three months, which were originally planned as the full length of the mission, it found evidence in rocks that acidic water flowed across parts of Mars and soaked the subsurface early in the planet's history. For nearly half of the mission -- 69 months -- Opportunity has been exploring sites on and near the western rim of Endeavour Crater, where even older rocks are exposed. The crater spans about 14 miles (22 kilometers) in diameter. Opportunity arrived from the northwest at a point corresponding to about the 10 o'clock position on the circle if north is noon; Perseverance Valley slices west to east at approximately the 8 o'clock position. Opportunity hustled southward to reach the crown of the valley in recent weeks. In mid-April it finished about two-and-a-half years on a rim segment called "Cape Tribulation." In seven drives between then and arriving at the destination on May 4, it covered 377 yards (345 meters), bringing the mission's total odometry to about 27.8 miles (44.7 kilometers). Opportunity and the next-generation Mars rover, Curiosity, as well as three active NASA Mars orbiters and surface missions to launch in 2018 and 2020 are all part of ambitious robotic exploration to understand Mars, which helps lead the way for sending humans to Mars in the 2030s. JPL, a division of Caltech in Pasadena, California, built Opportunity and manages the mission for NASA's Science Mission Directorate, Washington. For more information about Opportunity, visit: https://www.nasa.gov/rovers https://marsrovers.jpl.nasa.gov News Media Contact Guy Webster / Andrew Good Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 / 818-393-2433 guy.webs...@jpl.nasa.gov / andrew.c.g...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com
[meteorite-list] Movie Shows Ceres at Opposition from Sun
https://www.jpl.nasa.gov/news/news.php?feature=6845 Movie Shows Ceres at Opposition from Sun Jet Propulsion Laboratory May 16, 2017 NASA's Dawn spacecraft successfully observed Ceres at opposition on April 29, taking images from a position exactly between the sun and Ceres' surface. Mission specialists had carefully maneuvered Dawn into a special orbit so that the spacecraft could view Occator Crater, which contains the brightest area of Ceres, from this new perspective. A new movie shows these opposition images, with contrast enhanced to highlight brightness differences. The bright spots of Occator stand out particularly well on an otherwise relatively bland surface. Dawn took these images from an altitude of about 12,000 miles (20,000 kilometers). Based on data from ground-based telescopes and spacecraft that previously viewed planetary bodies at opposition, scientists correctly predicted that Ceres would appear brighter from this opposition configuration. This increase in brightness, or "surge," relates the size of the grains of material on the surface, as well as the porosity of those materials. The science motivation for performing these observations is further explained in the March issue of the Dawn Journal blog. Dawn's observations of Ceres during its more than two years there cover a broader range of illumination angles than almost any body in the solar system. This provides scientists with an opportunity to gain new insights into the surface properties. They are currently analyzing the new data. The new observations and images were largely unaffected by the loss of function of Dawn's third reaction wheel. The spacecraft is healthy and orients itself using its hydrazine thrusters. Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of Dawn mission participants, visit: https://dawn.jpl.nasa.gov/mission News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6425 elizabeth.lan...@jpl.nasa.gov 2017-140 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Moves Up Launch of Psyche Mission to a Metal Asteroid
https://www.jpl.nasa.gov/news/news.php?feature=6854 NASA Moves Up Launch of Psyche Mission to a Metal Asteroid Jet Propulsion Laboratory May 24, 2017 Psyche, NASA's Discovery Mission to a unique metal asteroid, has been moved up one year with launch in the summer of 2022, and with a planned arrival at the main belt asteroid in 2026 -- four years earlier than the original timeline. "We challenged the mission design team to explore if an earlier launch date could provide a more efficient trajectory to the asteroid Psyche, and they came through in a big way," said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington. "This will enable us to fulfill our science objectives sooner and at a reduced cost." The Discovery program announcement of opportunity had directed teams to propose missions for launch in either 2021 or 2023. The Lucy mission was selected for the first launch opportunity in 2021, and Psyche was to follow in 2023. Shortly after selection in January, NASA gave the direction to the Psyche team to research earlier opportunities. "The biggest advantage is the excellent trajectory, which gets us there about twice as fast and is more cost effective," said Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe. "We are all extremely excited that NASA was able to accommodate this earlier launch date. The world will see this amazing metal world so much sooner." The revised trajectory is more efficient, as it eliminates the need for an Earth gravity assist, which ultimately shortens the cruise time. In addition, the new trajectory stays farther from the sun, reducing the amount of heat protection needed for the spacecraft. The trajectory will still include a Mars gravity assist in 2023. "The change in plans is a great boost for the team and the mission," said Psyche Project Manager Henry Stone at NASA's Jet Propulsion Laboratory, Pasadena, California. "Our mission design team did a fantastic job coming up with this ideal launch opportunity." The Psyche spacecraft is being built by Space Systems Loral (SSL), Palo Alto, California. In order to support the new mission trajectory, SSL redesigned the solar array system from a four-panel array in a straight row on either side of the spacecraft to a more powerful five-panel x-shaped design, commonly used for missions requiring more capability. Much like a sports car, by combining a relatively small spacecraft body with a very high-power solar array design, the Psyche spacecraft will speed to its destination at a faster pace than is typical for a larger spacecraft. "By increasing the size of the solar arrays, the spacecraft will have the power it needs to support the higher velocity requirements of the updated mission," said SSL Psyche Program Manager Steve Scott. The Psyche Mission Psyche, an asteroid orbiting the sun between Mars and Jupiter, is made almost entirely of nickel-iron metal. As such, it offers a unique look into the violent collisions that created Earth and the terrestrial planets. The Psyche Mission was selected for flight earlier this year under NASA's Discovery Program, a series of lower-cost, highly focused robotic space missions that are exploring the solar system. The scientific goals of the Psyche mission are to understand the building blocks of planet formation and explore firsthand a wholly new and unexplored type of world. The mission team seeks to determine whether Psyche is the core of an early planet, how old it is, whether it formed in similar ways to Earth's core, and what its surface is like. The spacecraft's instrument payload will include magnetometers, multispectral imagers, and a gamma ray and neutron spectrometer. For more information about NASA's Psyche mission go to: http://www.nasa.gov/psyche News Media Contact D.C. Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 a...@jpl.nasa.gov Karin Valentine Arizona State University School of Earth and Space Exploration, Tempe 480-965-9345 karin.valent...@asu.edu Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-149 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] RIP Michael A'Hearn (1940-2017)
MICHAEL F. A'HEARN VISITATION AND FUNERAL NOTICE Mike passed away on Monday, May 29, 2017, at his home in University Park, MD. He had a deep love of science and gregarious nature, always able to make a positive difference in whatever he did. An obituary will be forthcoming. Mike was the beloved husband of Maxine C. A'Hearn; father of Brian J. (Zlata) of Oxford, UK, Kevin P. (Kanlayane) of Vienna, VA, and Patrick N. A'Hearn of Seattle, WA; grandfather of Sean, Brendan, Marie, Eliane, and Gabriel. Relatives and friends may call at: Visitation Wednesday, May 31, from 2 to 4 and 7 to 9 PM Collins Funeral Home 500 University Boulevard West Silver Spring, MD (Valet Parking) Funeral Thursday, June 1, at 10 AM Mass of Christian Burial Holy Redeemer Church Berwyn Rd & 49th Avenue College Park, MD Interment at Gate of Heaven Cemetery. Memorial contributions may be made to: S.O.M.E. (So Others Might Eat) 71 O Street, NW Washington, DC 20001 http://www.some.org or Catholic Relief Services P.O. Box 17090 Baltimore, MD 21297 http://www.crs.org __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Curiosity Rover Samples Active Linear Dune on Mars
https://www.jpl.nasa.gov/news/news.php?feature=6835 NASA Rover Samples Active Linear Dune on Mars Jet Propulsion Laboratory May 4, 2017 As it drives uphill from a band of rippled sand dunes, NASA's Curiosity Mars rover is toting a fistful of dark sand for onboard analysis that will complete the rover's investigation of those dunes. >From early February to early April, the rover examined four sites near a linear dune for comparison with what it found in late 2015 and early 2016 during its investigation of crescent-shaped dunes. This two-phase campaign is the first close-up study of active dunes anywhere other than Earth. Among the questions this Martian dune campaign is addressing is how winds shape dunes that are relatively close together, on the same side of the same mountain, into different patterns. Others include whether Martian winds sort grains of sand in ways that affect the distribution of mineral compositions, which would have implications for studies of Martian sandstones. "At these linear dunes, the wind regime is more complicated than at the crescent dunes we studied earlier," said Mathieu Lapotre of Caltech, in Pasadena, California, who helped lead the Curiosity science team's planning for the dune campaign. "There seems to be more contribution from the wind coming down the slope of the mountain here compared with the crescent dunes farther north." The linear dunes lie uphill and about a mile (about 1.6 kilometers) south from the crescent dunes. Both study locations are part of a dark-sand swath called the Bagnold Dunes, which stretches several miles in length. This dune field lines the northwestern flank of Mount Sharp, the layered mountain that Curiosity is climbing. "There was another key difference between the first and second phases of our dune campaign, besides the shape of the dunes," Lapotre said. "We were at the crescent dunes during the low-wind season of the Martian year and at the linear dunes during the high-wind season. We got to see a lot more movement of grains and ripples at the linear dunes." To assess wind strength and direction, the rover team now uses change-detection pairs of images taken at different times to check for movement of sand grains. The wind-sensing capability of the Curiosity's Rover Environmental Monitoring Station (REMS) is no longer available, though that instrument still returns other Mars-weather data daily, such as temperatures, humidity and pressure. Two of the six wind sensors on the rover's mast were found to be inoperable upon landing on Mars in 2012. The remainder provided wind information throughout the rover's prime mission and first two-year extended mission. A sample of sand that Curiosity scooped up from a linear dune is in the sample-handling device at the end of the rover's arm. One portion has been analyzed in the Sample Analysis at Mars (SAM) instrument inside the rover. The science team plans to deliver additional sample portions to SAM and to the rover's Chemistry and Mineralogy (CheMin) instrument. One factor in choosing to drive farther uphill before finishing analysis of the scooped sand is the status of Curiosity's rock-sampling drill, which has not been used on a rock since a problem with the drill feed mechanism appeared five months ago. Engineers are assessing how the use of vibration to deliver samples may affect the drill feed mechanism, which is used to move the drill bit forward and backwards. In addition, high winds at the linear-dunes location were complicating the process of pouring sample material into the entry ports for the laboratory instruments. "A balky brake appears to be affecting drill feed mechanism performance," said Curiosity Deputy Project Manager Steven Lee, of NASA's Jet Propulsion Laboratory, Pasadena, California. "In some cases, vibration has been observed to change feed effectiveness, so we're proceeding cautiously until we better understand the behavior. In the meantime, the engineering team is developing several methods to improve feed reliability." Curiosity landed near Mount Sharp in August 2012. It reached the base of the mountain in 2014 after successfully finding evidence on the surrounding plains that ancient Martian lakes offered conditions that would have been favorable for microbes if Mars has ever hosted life. Rock layers forming the base of Mount Sharp accumulated as sediment within ancient lakes billions of years ago. On Mount Sharp, Curiosity is investigating how and when the ancient habitable conditions known from the mission's earlier findings evolved into drier conditions that were less favorable for life. For more information about Curiosity, visit: http://mars.jpl.nasa.gov/msl News Media Contact Guy Webster / Andrew Good Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 / 818-393-2433 guy.webs...@jpl.nasa.gov / andrew.c.g...@jpl.nasa.gov Robert Perkins Caltech, Pasadena, Calif. 626-395-1862 / 6626-658-1053
[meteorite-list] Initial Results from the Close Approach of Asteroid 2014 JO25
https://cneos.jpl.nasa.gov/news/news196.html Initial Results from the Close Approach of Asteroid 2014 JO25 Center for NEO Studies (CNEOS) May 5, 2017 A relatively large asteroid called 2014 JO25 approached within 4.6 lunar distances (within 1.1 million miles or 1.8 million kilometers) of the Earth on April 19, 2017. This was the closest approach by an asteroid at least 600 meters in size since 4179 Toutatis, a 3 mile (5 kilometer) sized asteroid, approached within four lunar distances in September 2004. The close approach provided an outstanding opportunity to study the physical properties of the asteroid, and the images obtained by ground-based radars are comparable in resolution to those that could be obtained by a spacecraft flyby. 2014 JO25 was discovered by Al Grauer of the Catalina Sky Survey (CSS) near Tucson, Arizona in May 2014. The Catalina Sky Survey is a project of NASA's Near-Earth Object [NEO] Observations Program in collaboration with the University of Arizona. Figure 1: Part of the Catalina Sky Survey, this 1.52-meter Cassegrain telescope was used to discover 2014 JO25 in May 2014. The observatory is located just north of Tucson, Arizona in the Santa Catalina Mountains. Figure 1: Part of the Catalina Sky Survey, this 1.52-meter Cassegrain telescope was used to discover 2014 JO25 in May 2014. The observatory is located just north of Tucson, Arizona in the Santa Catalina Mountains. Shortly after its discovery Jet Propulsion Laboratory (JPL) astronomer Joe Masiero, a member of the NEOWISE science team, used observations made by the NEOWISE spacecraft in 2014 to estimate 2014 JO25's size as roughly 650 meters (2000 feet), and its optical albedo as 0.25. Albedo is the proportion of incident sunlight that a body reflects back into space. For comparison, the Moon has an albedo of 0.12, meaning that it reflects only 12% of the sunlight that reaches it. Based on initial estimates 2014 JO25's surface would be twice as reflective as the Moon's, fairly bright for an asteroid. Until the recent close pass, the asteroid's spectral class, rotation period, and pole direction were unknown. This close approach provided an opportunity for very detailed radar and optical observations, which allowed astronomers to better determine the characteristics of this unique object. But precision astrometry - measurements of the asteroid's position in space relative to stars in the background sky - was needed first to determine a more precise orbit, crucial for the radar observations. So in September 2016 Joe Masiero made a special effort to obtain more astrometric observations of 2014 JO25, which was distant at the time, and therefore very faint. He had to use the very large Gemini South 8.2-meter telescope on Cerro Pachon, Chile to make these measurements. These observations significantly reduced the orbital uncertainties for the asteroid. Using the more accurate orbit, Peter Veres of the Center for NEO Studies (CNEOS) at JPL looked through archival Pan-STARRS images taken in 2011, before the object was known to exist. These astrometric measurements were crucial for reducing the pointing uncertainties for this close pass in April 2017 and enabled the successful radar observations. Your browser does not support the video tag. You can the video instead. Figure 2: This animation shows the orbit of 2014 JO25 about the Sun. The orbit is inclined ~25 degrees with respect to the ecliptic; perihelion at 0.24 AU and aphelion at 3.9 AU [for reference Jupiter orbits the Sun at 5.2 AU]. The orbit of 2014 JO25 seems to resemble that of an Encke-like comet. For a high resolution version, download the video for external display. (NASA/JPL) Radar observations were performed at the National Science Foundation's Arecibo Observatory equipped with the NASA planetary radar system by a team led by Patrick Taylor of Arecibo Observatory between April 15-21, and at NASA's Goldstone Solar System Radar by a team led by Lance Benner of JPL from April 16-21. These dates cover the actual closest approach time at 08:24 EDT on April 19, and due to the proximity of the asteroid, the observations produced hundreds of radar images with resolutions of 7.5 meters/pixel from both observatories and a smaller number of images at 3.75 meter/pixel resolution at Goldstone. Figure 3: This sequence of images was obtained by NASA's 70-meter antenna at Goldstone near Barstow, California, on 18 April 2017 - the day before 2014 JO25's closest approach. The double-lobed asteroid safely passed by the Earth at a distance of 1.8 million kilometers (or ~4.6 times the average distance from Earth to the Moon (NASA/JPL). Figure 3: This sequence of images was obtained by NASA's 70-meter antenna at Goldstone near Barstow, California, on 18 April 2017 - the day before 2014 JO25's closest approach. The double-lobed asteroid safely passed by the Earth at a distance of 1.8 million kilometers (or ~4.6 times the
[meteorite-list] Dawn Journal - April 29, 2017
https://dawnblog.jpl.nasa.gov/2016/04/29/dawn-journal-april-29-2/ Dawn Journal by Dr. Marc Rayman April 29, 2017 Dear Glutdawnous Readers, The distant dwarf planet that Dawn is circling is full of mystery and yet growing ever more familiar. Ceres, which only last year was hardly more than a fuzzy blob against the stars, is now a richly detailed world, and our portrait grows more elaborate every day. Having greatly surpassed all of its original objectives, the reliable explorer is gathering still more data from its unique vantage point. Everyone who hungers for new knowledge about the cosmos or for bold adventures far from Earth can share in the sumptuous feast Dawn has been serving. One of the major objectives of the mission was to photograph 80 percent of Ceres' vast landscape with a resolution of 660 feet (200 meters) per pixel. That would provide 150 times the clarity of the powerful Hubble Space Telescope. Dawn has now photographed 99.8 percent with a resolution of 120 feet (35 meters) per pixel. [Haulani Crater in Enhanced Color] This image of Haulani Crater uses color pictures Dawn acquired during its third mapping orbit at an altitude of 915 miles (1,470 kilometers). We saw the crater from the same altitude in black and white here. This false color picture highlights differences in composition or other properties that your eye would not be able to detect. In this color scheme, blue is associated with geologically young material, consistent with the description of the black and white image as showing a young crater. It is easy to see that the surrounding region was affected by the formation of the crater. (The last picture below shows the area around another crater that was altered by an impact.) Also note the variation in terrain within the crater, including a prominent ridge in the center. The crater is 21 miles (34 kilometers) in diameter. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA This example of Dawn's extraordinary productivity may appear to be the limit of what it could achieve. After all, the spaceship is orbiting at an altitude of only 240 miles (385 kilometers), closer to the ground than the International Space Station is to Earth, and it will never go lower for more pictures. But it is already doing more. Since April 11, instead of photographing the scenery directly beneath it, Dawn has been aiming its camera to the left and forward as it orbits and Ceres rotates. By May 25, it will have mapped most of the globe from that angle. Then it will start all over once more, looking instead to the right and forward from May 27 through July 10. The different perspectives on the terrain make stereo views, which scientists can combine to bring out the full three dimensionality of the alien world. Dawn already accomplished this in its third mapping orbit from four times its current altitude, but now that it is seeing the sights from so much lower, the new topographical map will be even more accurate. [Oxo Crater at LAMO] Dawn captured this view of Oxo Crater on Jan. 16 from an altitude of 240 miles (385 kilometers). Although it is a modest six miles (10 kilometers) across, it is a particularly interesting crater. This is the only location (so far) on Ceres where Dawn has clearly detected water. Oxo is the second brightest area on Ceres. Only Occator Crater is brighter. Oxo also displays a uniquely large 'slump' in its rim, where a mass of material has dropped below the surface. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA Dawn is also earning extra credit on its assignment to measure the energy of gamma rays and neutrons. We have discussed before how the gamma ray and neutron detector (GRaND) can reveal the atomic composition down to about a yard (meter) underground, and last month we saw initial findings about the distribution of hydrogen. However, Ceres' nuclear glow is very faint. Scientists already have three times as much GRaND data from this low altitude as they had required, and both spectrometers in the instrument will continue to collect data. In effect, Dawn is achieving a longer exposure, making its nuclear picture of Ceres brighter and sharper. In December we explained how using the radio signal to track the probe's movements allows scientists to chart the gravity field and thereby learn about the interior of Ceres, revealing regions of higher and lower density. Once again, Dawn performed even better than expected and achieved the mission's planned accuracy in the third mapping orbit. Because the strength of the dwarf planet's gravitational tug depends on the distance, even finer measurements of how it varies from location to location are possible in this final orbit. Thanks to the continued smooth operation of the mission, scientists now have a gravitational map fully twice as accurate as they had anticipated. With additional measurements, they may be able to squeeze out a little more detail, perhaps
[meteorite-list] Dawn Observing Ceres; 3rd Reaction Wheel Malfunctions
https://www.jpl.nasa.gov/news/news.php?feature=6830 Dawn Observing Ceres; 3rd Reaction Wheel Malfunctions Jet Propulsion Laboratory Arpil 26, 2017 Mission Status Report NASA's Dawn spacecraft is preparing to observe Ceres on April 29 from an "opposition" position, directly between the dwarf planet's mysterious Occator Crater and the sun. This unique geometry may yield new insights about the bright material in the center of the crater. While preparing for this observation, one of Dawn's two remaining reaction wheels stopped functioning on April 23. By electrically changing the speed at which these gyroscope-like devices spin, Dawn controls its orientation in the zero-gravity, frictionless conditions of space. The team discovered the situation during a scheduled communications session on April 24, diagnosed the problem, and returned the spacecraft to its standard flight configuration, still with hydrazine control, on April 25. The failure occurred after Dawn completed its five-hour segment of ion thrusting on April 22 to adjust its orbit, but before the shorter maneuver scheduled for April 23-24. The orbit will still allow Dawn to perform its opposition measurements. The reaction wheel's malfunctioning will not significantly impact the rest of the extended mission at Ceres. Dawn completed its prime mission in June 2016, and is now in an extended mission. It has been studying Ceres for more than two years, and before that, the spacecraft orbited giant asteroid Vesta, sending back valuable data and images. Dawn launched in 2007. The Dawn operations team has been well prepared to deal with the loss of the reaction wheel. The spacecraft is outfitted with four reaction wheels. It experienced failures of one of the wheels in 2010, a year before it entered orbit around Vesta, and another in 2012, as it was completing its exploration of that fascinating world. (See issues with these devices). When a third reaction wheel stopped working this week, the spacecraft correctly responded by entering one of its safe modes and assigning control of its orientation to its hydrazine thrusters. Today, Dawn's elliptical orbit will bring it from an altitude of 17,300 miles (27,900 kilometers) to 15,800 miles (25,400 kilometers) above Ceres. The Dawn mission is managed by NASA's Jet Propulsion Laboratory in Pasadena, California, for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: https://dawn.jpl.nasa.gov/mission More information about Dawn is available at the following sites: https://www.nasa.gov/dawn https://dawn.jpl.nasa.gov News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6425 elizabeth.lan...@jpl.nasa.gov 2017-125 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Detecting Life in the Driest Place on Earth
https://www.jpl.nasa.gov/news/news.php?feature=6821 Detecting Life in the Driest Place on Earth Jet Propulsion Laboratory April 20, 2017 Few places are as hostile to life as Chile's Atacama Desert. It's the driest place on Earth, and only the hardiest microbes survive there. Its rocky landscape has lain undisturbed for eons, exposed to extreme temperatures and radiation from the sun. If you can find life here, you might be able to find it in an even harsher environment -- like the surface of Mars. That's why a team of researchers from NASA and several universities visited the Atacama in February. They spent 10 days testing devices that could one day be used to search for signs of life on other worlds. That group included a team from NASA's Jet Propulsion Laboratory in Pasadena, California, working on a portable chemistry lab called the Chemical Laptop. With just a small water sample, the Laptop can check for amino acids, the organic molecules that are widespread in our solar system and considered the building blocks of all life as we know it. Liquid-based analysis techniques have been shown to be orders of magnitude more sensitive than gas-based methods for the same kinds of samples. But when you scoop up a sample from Mars, the amino acids you're looking for will be trapped inside of or chemically bonded to minerals. To break down those bonds, JPL has designed another piece of technology, a subcritical water extractor that would act as the "front end" for the Laptop. This extractor uses water to release the amino acids from a soil sample, leaving them ready to be analyzed by the Chemical Laptop. "These two pieces of technology work together so that we can search for biosignatures in solid samples on rocky or icy worlds," said Peter Willis of JPL, the project's principal investigator. "The Atacama served as a proving ground to see how this technology would work on an arid planet like Mars." To find life, just add water Willis' team revisited an Atacama site he first went to in 2005. At that time, the extractor he used was manually operated; in February, the team used an automated extractor designed by Florian Kehl, a postdoctoral researcher at JPL. The extractor ingests soil and regolith samples and mixes them with water. Then, it subjects the samples to high pressure and temperature to get the organics out. "At high temperatures, water has the ability to dissolve the organic compounds from the soil," Kehl said. "Think of a tea bag: in cold water, not much happens. But when you add hot water, the tea releases an entire bouquet of molecules that gives the water a particular flavor, color and smell." To remove the amino acids from those minerals, the water has to get much hotter than your ordinary cup of tea: Kehl said the extractor is currently able to reach temperatures as high as 392 degrees Fahrenheit (200 degrees Celsius). Liquid samples would be more readily available on ocean worlds like Jupiter's moon Europa, Kehl said. There, the extractor might still be necessary, as amino acids could be bonded to minerals mixed into the ice. They also may be present as part of larger molecules, which the extractor could break into smaller building blocks before analyzing them with the Chemical Laptop. Once the extractor has prepared its samples, the Laptop can do its work. NASA's own tricorder The Chemical Laptop checks liquid samples for a set of 17 amino acids -- what the team refers to as "the Signature 17." By looking at the types, amounts and geometries of these amino acids in a sample, it's possible to infer the presence of life. "All these molecules 'like' being in water," said Fernanda Mora of JPL, the Chemical Laptop's lead scientist. "They dissolve in water and they don't evaporate easily, so they're much easier to detect in water." The Laptop mixes liquid samples with a fluorescent dye, which attaches to amino acids and makes it possible to detect them when illuminated by a laser. Then, the sample is injected onto a separation microchip. A voltage is applied between the two ends of the channel, causing the amino acids to move at different speeds towards the end, where the laser is shining. Amino acids can be identified by how quickly they move through the channel. As the molecules pass through the laser, they emit light that is used to quantify how much of each amino acid is present. "The idea is to automate and miniaturize all the steps you would do manually in a chemistry lab on Earth," Mora said. "That way, we can do the same analyses on another world simply by sending commands with a computer." The near-term goal is to integrate the extractor and Chemical Laptop into a single, automated device. It would be tested during future field campaigns to the Atacama Desert with a team of researchers led by Brian Glass of NASA's Ames Research Center in Mountain View, California. "These are some of the hardest samples to analyze you
[meteorite-list] Landslides on Ceres Reflect Ice Content
https://www.jpl.nasa.gov/news/news.php?feature=6820 Landslides on Ceres Reflect Ice Content Jet Propulsion Laboratory April 19, 2017 As NASA's Dawn spacecraft continues exploring Ceres, evidence mounts that the enigmatic dwarf planet retains a significant amount of water ice. A new study in the journal Nature Geoscience adds to this picture, showing how ice may have shaped the variety of landslides seen on Ceres today. "Images from Dawn show that landslides, many of which are similar to those seen on Earth, are very common on Ceres, and further the case that Ceres has a lot of water ice involved in its structure," said Britney Schmidt, who led the study. She is an associate of the Dawn science team and assistant professor at Georgia Institute of Technology in Atlanta. Types of Landslides Schmidt and colleagues identified three types of landslides. Type I, which are relatively round and large, have thick "toes" at their ends. They look similar to rock glaciers and icy landslides on Earth. Type I landslides are mostly found at high latitudes on Ceres, which is also where the most ice is thought to reside just beneath the surface, suggesting they involve the most ice of any of the flow features. Three small Type 1 flows are found in Oxo Crater, a tiny bright crater in the northern hemisphere that hosts an ice deposit at the surface. Type II features are often thinner and longer than Type I, and are the most common type of landslide on Ceres. The landslide deposits appear similar to those left behind by avalanches seen on Earth. Ceres' Type III features may involve a brief melting of some of the ice within the soil-like regolith, causing the material to flow like mud before refreezing. These landslides are always associated with large impact craters, and may have formed when an impact event melts subsurface ice on Ceres. These features have similar appearances to ejected material from craters in the icy regions of Mars and on Jupiter's moon Ganymede. "The locations of these different types of features reinforces the idea that the shallow subsurface of Ceres is a mixture of ice and rock, and that ice is most plentiful near the surface at the poles," Schmidt said. Scientists were also surprised at just how many landslides have occurred on Ceres in general. About 20 to 30 percent of craters greater than 6 miles (10 kilometers) wide have some type of landslide associated with them. Such widespread "ground ice" features, which formed from of a mixture of rock and ice, had only been observed before on Earth and Mars. Implications and Future Observations Based on the shape and distribution of landslides on Ceres, study authors estimate that the ice in the upper few tens of meters of Ceres may range from 10 percent to 50 percent by volume. "These kinds of flows are not seen on bodies such as Vesta, which Dawn studied from 2011 to 2012, because the regolith is devoid of water," said Carol Raymond, deputy principal investigator for the Dawn mission, based at NASA's Jet Propulsion Laboratory, Pasadena, California. Now in its extended mission phase, Dawn is using its ion engine to swivel the plane of its orbit around Ceres to prepare for observations from a new orbit and orientation. At the end of April, the spacecraft will be directly between the sun and the mysterious Occator Crater. In this geometry, Dawn may deliver new insights about the reflective material of Ceres' most famous "bright spot," the highly reflective center of Occator that has been named Cerealia Facula. The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: https://dawn.jpl.nasa.gov/mission More information about Dawn is available at the following sites: https://www.nasa.gov/dawn https://dawn.jpl.nasa.gov News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, CA 818-354-6425 elizabeth.lan...@jpl.nasa.gov 2017-114 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA's Mars Rover Opportunity Leaves 'Tribulation'
https://www.jpl.nasa.gov/news/news.php?feature=6819 NASA's Mars Rover Opportunity Leaves 'Tribulation' Jet Propulsion Laboratory April 19, 2017 NASA's senior Mars rover, Opportunity, is departing "Cape Tribulation," a crater-rim segment it has explored since late 2014, southbound for its next destination, "Perseverance Valley." The rover team plans observations in the valley to determine what type of fluid activity carved it billions of years ago: water, wind, or flowing debris lubricated by water. A color panorama of a ridge called "Rocheport" provides both a parting souvenir of Cape Tribulation and also possible help for understanding the valley ahead. The view was assembled from multiple images taken by Opportunity's panoramic camera. "The degree of erosion at Rocheport is fascinating," said Opportunity Deputy Principal Investigator Ray Arvidson, of Washington University in St. Louis. "Grooves run perpendicular to the crest line. They may have been carved by water or ice or wind. We want to see as many features like this on the way to Perseverance Valley as we can, for comparison with what we find there." Perseverance Valley is about two football fields long. It cuts downward west to east across the western rim of Endeavour Crater. The crater is about 14 miles (22 kilometers) in diameter, with a segmented rim that exposes the oldest rocks ever investigated in place on Mars. Opportunity has less than four football fields' distance of driving to reach the top of the valley after departing Cape Tribulation, a raised segment about 3 miles (5 kilometers) long on the crater's western rim. In 68 months since reaching Endeavour Crater, Opportunity has explored "Cape York," "Solander Point" and "Murray Ridge" before reaching Cape Tribulation about 30 months ago. "Cape Byron," the next raised segment to the south, contains Perseverance Valley and is separated from Tribulation by a gap of flatter ground. Five drives totaling about 320 feet (98 meters) since the beginning of April have brought Opportunity to a boundary area where Cape Tribulation meets the plain surrounding the crater. Cape Tribulation has been the site of significant events in the mission. There, in 2015, Opportunity surpassed a marathon-race distance of total driving since its 2004 landing on Mars. It climbed to the highest-elevation viewpoint it has reached on Endeavour's rim. In a region of Tribulation called "Marathon Valley," it investigated outcrops containing clay minerals that had been detected from orbit. There were some name-appropriate Tribulation experiences, as well. The rover team has coped with loss of reliability in Opportunity's non-volatile "flash" memory since 2015. With flash memory unavailable, each day's observations are lost if not radioed homeward the same day. "From the Cape Tribulation departure point, we'll make a beeline to the head of Perseverance Valley, then turn left and drive down the full length of the valley, if we can," Arvidson said. "It's what you would do if you were an astronaut arriving at a feature like this: Start at the top, looking at the source material, then proceed down the valley, looking at deposits along the way and at the bottom." Clues to how the valley was carved could come from the arrangement of different sizes of rocks and gravel in the deposits. He said, "If it was a debris flow, initiated by a little water, with lots of rocks moving downhill, it should be a jumbled mess. If it was a river cutting a channel, we may see gravel bars, crossbedding, and what's called a 'fining upward' pattern of sediments, with coarsest rocks at the bottom." Another pattern that could be evidence of flowing water would be if elongated pieces of gravel in a deposited bed tend to be stacked leaning in the same direction, providing a record of the downstream flow direction. Now more than 13 years into a mission originally scheduled to last three months on Mars, Opportunity remains unexpectedly capable of continued exploration. It has driven about four-tenths of a mile (two-thirds of a kilometer) since the start of 2017, bringing the total traverse so far to 27.6 miles (44.4 kilometers). The current season on Mars is past the period when global dust storms might arise and curtail Opportunity's solar power. Opportunity and the next-generation Mars rover, Curiosity, as well as three active NASA Mars orbiters, and surface missions to launch in 2018 and 2020 are all part of a legacy of robotic exploration which is helping to lay the groundwork for sending humans there in the 2030s. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, built Opportunity and manages the mission for NASA's Science Mission Directorate, Washington. For more information about Opportunity, visit: http://www.nasa.gov/rovers http://marsrovers.jpl.nasa.gov News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278
[meteorite-list] NASA Scientists to Discuss Search for Habitable Planets, Signs of Life off Earth
April 19, 2017 MEDIA ADVISORY M17-046 NASA Scientists to Discuss Search for Habitable Planets, Signs of Life off Earth NASA scientists from across the agency will present their latest findings and perspectives on topics ranging from the origins and evolution of life on Earth to the search for habitable environments and life in our solar system and beyond during the 2017 Astrobiology Science Conference, April 24-28 in Mesa, Arizona. Among the scientists scheduled to present at the conference are: * Giada Arney from NASA's Goddard Space Flight Center in Greenbelt, Maryland, will discuss organic haze on Earthlike planets as a possible biosignatures * Morgan Cable at NASA's Jet Propulsion Laboratory in Pasadena, California, will talk about mechanisms for enrichment of organics in Enceladus plumes * John Grunsfeld, former NASA astronaut and associate administrator for science, will deliver a presentation on next-generation space telescopes for terrestrial exoplanet characterization and the search for biosignatures * Michael Mumma from Goddard will discuss methane as a possible messenger in the search for life on Mars * Andrew Pohorille at NASA's Ames Research Center in California's Silicon Valley will talk about the origin and evolution of information transfer in biological systems On Sunday, April 23, NASA will hold a town hall meeting from 12:30 to 6 p.m. PDT at the Phoenix Marriott Mesa Hotel to solicit feedback from the astrobiology community on the Europa Lander Science Definition Team report. For more information on this town hall, contact Curt Niebur at curt.nie...@nasa.gov. The Roadmaps to Ocean Worlds (ROW) team, chartered to identify science objectives and exploration roadmaps for ocean worlds, will hold a town hall from 12:15 to 1:15 p.m. on Monday, April 24, to share its progress and gather input from the astrobiology community. Arizona State University (ASU), host of the conference, will hold two free public events at the Phoenix Marriott Mesa Hotel. The ASU Beyond Center will sponsor a program from 7 to 8:30 p.m. Tuesday, April 25 titled "Where a Second Example of Life Might be Discovered in the Next Century." On Thursday, April 26, the ASU Origins Project will sponsor a program from 6:30 to 8:30 p.m. on "How Astrobiology and Planetary Science Inform a Perspective of Planetary Stewardship." The conference will take place at the Mesa Convention Center, located at 263 N. Center Street, and the Phoenix Marriott Mesa Hotel, at 200 North Centennial Way. The Lunar and Planetary Institute is responsible for conference logistics. Media may register to attend. For more information, including links to the program, media advisories and contact information, visit: https://www.hou.usra.edu/meetings/abscicon2017/registration/registration/ Select events will be live streamed, and schedules are available at: http://astrobiology.nasa.gov/livestream For information about NASA astrobiology visit: https://astrobiology.nasa.gov/ -end- Press Contacts Dwayne Brown / Laurie Cantillo Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Radar Spots Relatively Large Asteroid Prior to Flyby (2014 JO25)
https://www.jpl.nasa.gov/news/news.php?feature=6817 NASA Radar Spots Relatively Large Asteroid Prior to Flyby Jet Propulsion Laboratory April 18, 2017 Radar images of asteroid 2014 JO25 were obtained in the early morning hours on Tuesday, with NASA's 70-meter (230-foot) antenna at the Goldstone Deep Space Communications Complex in California. The images reveal a peanut-shaped asteroid that rotates about once every five hours. The images have resolutions as fine as 25 feet (7.5 meters) per pixel. Asteroid 2014 JO25 was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona -- a project of NASA's Near-Earth Objects Observations Program in collaboration with the University of Arizona. The asteroid will fly safely past Earth on Wednesday at a distance of about 1.1 million miles (1.8 million kilometers), or about 4.6 times the distance from Earth to the moon. The encounter is the closest the object will have come to Earth in 400 years and will be its closest approach for at least the next 500 years. "The asteroid has a contact binary structure - two lobes connected by a neck-like region," said Shantanu Naidu, a scientist from NASA's Jet Propulsion Laboratory in Pasadena, California, who led the Goldstone observations. "The images show flat facets, concavities and angular topography." The largest of the asteroid's two lobes is estimated to be 2,000 feet (620 meters) across. Radar observations of the asteroid also have been conducted at the National Science Foundation's Arecibo Observatory in Puerto Rico. Additional radar observations are being conducted at both Goldstone and Arecibo on April 19 20, and 21, and could provide images with even higher resolution. Radar has been used to observe hundreds of asteroids. When these small, natural remnants of the formation of the solar system pass relatively close to Earth, deep space radar is a powerful technique for studying their sizes, shapes, rotation, surface features, and roughness, and for more precise determination of their orbital path. NASA's Jet Propulsion Laboratory, Pasadena, California, manages and operates NASA's Deep Space Network, including the Goldstone Solar System Radar, and hosts the Center for Near-Earth Object Studies for NASA's Near-Earth Object Observations Program within the agency's Science Mission Directorate. More information about asteroids and near-Earth objects can be found at: http://cneos.jpl.nasa.gov http://www.jpl.nasa.gov/asteroidwatch For more information about NASA's Planetary Defense Coordination Office, visit: http://www.nasa.gov/planetarydefense For asteroid and comet news and updates, follow AsteroidWatch on Twitter: http://twitter.com/AsteroidWatch News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, California 818-393-9011 a...@jpl.nasa.gov 2017-111 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Invests in 22 Visionary Exploration Concepts
https://www.jpl.nasa.gov/news/news.php?feature=6808 NASA Invests in 22 Visionary Exploration Concepts Jet Propulsion Laboratory April 7, 2017 A mechanical rover inspired by a Dutch artist. A weather balloon that recharges its batteries in the clouds of Venus. These are just two of the five ideas that originated at NASA's Jet Propulsion Laboratory in Pasadena, California, and are advancing for a new round of research funded by the agency. In total, the space agency is investing in 22 early-stage technology proposals that have the potential to transform future human and robotic exploration missions, introduce new exploration capabilities, and significantly improve current approaches to building and operating aerospace systems. The 2017 NASA Innovative Advanced Concepts (NIAC) portfolio of Phase I concepts covers a wide range of innovations selected for their potential to revolutionize future space exploration. Phase I awards are valued at approximately $125,000, for nine months, to support initial definition and analysis of their concepts. If these basic feasibility studies are successful, awardees can apply for Phase II awards. "The NIAC program engages researchers and innovators in the scientific and engineering communities, including agency civil servants," said Steve Jurczyk, associate administrator of NASA's Space Technology Mission Directorate. "The program gives fellows the opportunity and funding to explore visionary aerospace concepts that we appraise and potentially fold into our early stage technology portfolio." The selected 2017 Phase I proposals are: * A Synthetic Biology Architecture to Detoxify and Enrich Mars Soil for Agriculture, Adam Arkin, University of California, Berkeley â*A Breakthrough Propulsion Architecture for Interstellar Precursor Missions, John Brophy, NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California * Evacuated Airship for Mars Missions, John-Paul Clarke, Georgia Institute of Technology in Atlanta * Mach Effects for In Space Propulsion: Interstellar Mission, Heidi Fearn, Space Studies Institute in Mojave, California * Pluto Hop, Skip, and Jump, Benjamin Goldman, Global Aerospace Corporation in Irwindale, California * Turbolift, Jason Gruber, Innovative Medical Solutions Group in Tampa, Florida * Phobos L1 Operational Tether Experiment, Kevin Kempton, NASA's Langley Research Center in Hampton, Virginia * Gradient Field Imploding Liner Fusion Propulsion System, Michael LaPointe, NASA's Marshall Space Flight Center in Huntsville, Alabama * Massively Expanded NEA Accessibility via Microwave-Sintered Aerobrakes, John Lewis, Deep Space Industries, Inc., in Moffett Field, California * Dismantling Rubble Pile Asteroids with Area-of-Effect Soft-bots, Jay McMahon, University of Colorado, Boulder * Continuous Electrode Inertial Electrostatic Confinement Fusion, Raymond Sedwick, University of Maryland, College Park * Sutter: Breakthrough Telescope Innovation for Asteroid Survey Missions to Start a Gold Rush in Space, Joel Sercel, TransAstra in Lake View Terrace, California * Direct Multipixel Imaging and Spectroscopy of an Exoplanet with a Solar Gravity Lens Mission, Slava Turyshev, JPL * Solar Surfing, Robert Youngquist, NASA's Kennedy Space Center in Florida * A Direct Probe of Dark Energy Interactions with a Solar System Laboratory, Nan Yu, JPL "The 2017 NIAC Phase I competition has resulted in an excellent set of studies. All of the final candidates were outstanding," said Jason Derleth, NIAC program executive. "We look forward to seeing how each new study will expand how we explore the universe." Phase II studies allow awardees time to refine their designs and explore aspects of implementing the new technology. This year's Phase II portfolio addresses a range of leading-edge concepts, including: a Venus probe using in-situ power and propulsion to study the Venusian atmosphere, and novel orbital imaging data derived from stellar echo techniques -- measurement of the variation in a star's light caused by reflections off of distant worlds -- to detect exoplanets, which are planets outside our solar system. Awards under Phase II of the NIAC program can be worth as much as $500,000, for two-year studies, and allow proposers to further develop Phase I concepts that successfully demonstrated initial feasibility and benefit. The selected 2017 Phase II proposals are: * Venus Interior Probe Using In-situ Power and Propulsion, Ratnakumar Bugga, JPL * Remote Laser Evaporative Molecular Absorption Spectroscopy Sensor System, Gary Hughes, California Polytechnic State University in San Luis Obispo * Brane Craft Phase II, Siegfried Janson, The Aerospace Corporation in El Segundo, California * Stellar Echo Imaging of Exoplanets, Chris Mann, Nanohmics, Inc., Austin, Texas * Automaton Rover for Extreme Environments, Jonathan Sauder, JPL * Optical Mining of Asteroids, Moons, and Planets to Enable Sustainable
[meteorite-list] Asteroid 2014 JO25 to Fly Safely Past Earth on April 19
https://www.jpl.nasa.gov/news/news.php?feature=6807 Asteroid to Fly Safely Past Earth on April 19 Jet Propulsion Laboratory April 6, 2017 A fairly large asteroid discovered nearly three years ago will fly safely past Earth on April 19 at a distance of about 1.1 million miles (1.8 million kilometers), or about 4.6 times the distance from Earth to the moon. Although there is absolutely no chance that the asteroid will collide with our planet, this will be a very close approach for an asteroid of this size. The asteroid, known as 2014 JO25, was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona -- a project of NASA's NEO Observations Program in collaboration with the University of Arizona. (An NEO is a near-Earth object). Contemporary measurements by NASA's NEOWISE mission indicate that the asteroid is roughly 2,000 feet (650 meters) in size, and that its surface is about twice as reflective as that of the moon. At this time very little else is known about the object's physical properties, even though its trajectory is well known. The asteroid will approach Earth from the direction of the sun and will become visible in the night sky after April 19. It is predicted to brighten to about magnitude 11, when it could be visible in small optical telescopes for one or two nights before it fades as the distance rapidly increases. Asteroids pass within this distance of Earth around two to seven times a week, but this upcoming close approach is the closest by any known asteroid of this size, or larger, since asteroid Toutatis approached within about four lunar distances in September 2004. The next known encounter of an asteroid of comparable size will occur in 2027 when the half-mile-wide (800-meter-wide) asteroid 1999 AN10 will fly by at one lunar distance, about 236,000 miles (380,000 kilometers). The April 19 encounter provides an outstanding opportunity to study this asteroid, and astronomers plan to observe it with telescopes around the world to learn as much about it as possible. Radar observations are planned at NASA's Goldstone Solar System Radar in California and the National Science Foundation's Arecibo Observatory in Puerto Rico, and the resulting radar images could reveal surface details as small as a few meters. The encounter on April 19 is the closest this asteroid has come to Earth for at least the last 400 years and will be its closest approach for at least the next 500 years. Also on April 19, the comet PanSTARRS (C/2015 ER61) will make its closest approach to Earth, at a very safe distance of 109 million miles (175 million kilometers). A faint fuzzball in the sky when it was discovered in 2015 by the Pan-STARRS NEO survey team using a telescope on the summit of Haleakala, Hawaii, the comet has brightened considerably due to a recent outburst and is now visible in the dawn sky with binoculars or a small telescope. JPL manages and operates NASA's Deep Space Network, including the Goldstone Solar System Radar, and hosts the Center for Near-Earth Object Studies for NASA's Near-Earth Object Observations Program, an element of the Planetary Defense Coordination Office within the agency's Science Mission Directorate. More information about asteroids and near-Earth objects can be found at: http://cneos.jpl.nasa.gov http://www.jpl.nasa.gov/asteroidwatch For more information about NASA's Planetary Defense Coordination Office, visit: http://www.nasa.gov/planetarydefense For asteroid and comet news and updates, follow AsteroidWatch on Twitter: twitter.com/AsteroidWatch News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 a...@jpl.nasa.gov 2017-100 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Ceres' Temporary Atmosphere Linked to Solar Activity
https://www.jpl.nasa.gov/news/news.php?feature=6802 Ceres' Temporary Atmosphere Linked to Solar Activity Jet Propuslion Laboratory April 6, 2017 Scientists have long thought that Ceres may have a very weak, transient atmosphere, but mysteries lingered about its origin and why it's not always present. Now, researchers suggest that this temporary atmosphere appears to be related to the behavior of the sun, rather than Ceres' proximity to the sun. The study was conducted by scientists from NASA's Dawn mission and others who previously identified water vapor at Ceres using other observatories. "We think the occurrence of Ceres' transient atmosphere is the product of solar activity," said Michaela Villarreal, lead author of the new study in the Astrophysical Journal Letters and researcher at the University of California, Los Angeles. Ceres is the largest object in the asteroid belt that lies between Mars and Jupiter. When energetic particles from the sun hit exposed ice and ice near the surface of the dwarf planet, it transfers energy to the water molecules as they collide. This frees the water molecules from the ground, allowing them to escape and create a tenuous atmosphere that may last for a week or so. "Our results also have implications for other airless, water-rich bodies of the solar system, including the polar regions of the moon and some asteroids," said Chris Russell, principal investigator of the Dawn mission, also at UCLA. "Atmospheric releases might be expected from their surfaces, too, when solar activity erupts." Before Dawn arrived in orbit at Ceres in 2015, evidence for an atmosphere had been detected by some observatories at certain times, but not others, suggesting that it is a transient phenomenon. In 1991, the International Ultraviolet Explorer satellite detected hydroxyl emission from Ceres, but not in 1990. Then, in 2007, the European Southern Observatory's Very Large Telescope searched for a hydroxide emission, but came up empty. The European Space Agency's Herschel Space Observatory detected water in the possible weak atmosphere, or "exosphere," of Ceres on three occasions, but did not on a fourth attempt. As Dawn began its thorough study of Ceres in March 2015, scientists found ample evidence for water in the form of ice. The spacecraft's gamma ray and neutron detector (GRaND) has found that the uppermost surface is rich in hydrogen, which is consistent with broad expanses of water ice. This ice is nearer to the surface at higher latitudes, where temperatures are lower, a 2016 study published in the journal Science found. Ice has been detected directly at the small bright crater called Oxo and in at least one of the craters that are persistently in shadow in the northern hemisphere. Other research has suggested that persistently shadowed craters are likely to harbor ice. Additionally, the shapes of craters and other features are consistent with significant water-ice content in the crust. Because of this evidence for abundant ice, many scientists think that Ceres' exosphere is created in a process similar to what occurs on comets, even though they are much smaller. In that model, the closer Ceres gets to the sun, the more water vapor is released because of ice sublimating near or at the surface. But the new study suggests comet-like behavior may not explain the mix of detections and non-detections of a weak atmosphere. "Sublimation probably is present, but we don't think it's significant enough to produce the amount of exosphere that we're seeing," Villarreal said. Villarreal and colleagues showed that past detections of the transient atmosphere coincided with higher concentrations of energetic protons from the sun. Non-detections coincided with lower concentrations of these particles. What's more, the best detections of Ceres' atmosphere did not occur at its closest approach to the sun. This suggests that solar activity, rather than Ceres' proximity to the sun, is a more important factor in generating an exosphere. The research began with a 2016 Science study led by Chris Russell. The study, using GRaND data, suggested that, during a six-day period in 2015, Ceres had accelerated electrons from the solar wind to very high energies. In its orbital path, Ceres is currently getting closer to the sun. But the sun is now in a particularly quiet period, expected to last for several more years. Since their results indicate Ceres' exosphere is related to solar activity, study authors are predicting that the dwarf planet will have little to no atmosphere for some time. However, they recommend that other observatories monitor Ceres for future emissions. Dawn is now in its extended mission and studying Ceres in a highly elliptical orbit. Engineers are maneuvering the spacecraft to a different orbital plane so that Ceres can be viewed in a new geometry. The primary science objective is to measure cosmic rays to help
[meteorite-list] Dawn Journal - March 30, 2017
http://dawn.jpl.nasa.gov/mission/journal_03_30_17.html Dawn Journal Dr. Marc Rayman March 30, 2017 Dear Leonardo dawn Vinci, Micheldawngelo and Other Artistic Readers, Now in its third year of orbiting a distant dwarf planet, a spacecraft from Earth is as active as ever. Like a master artist, Dawn is working hard to add fine details to its stunning portrait of Ceres. In this phase of its extended mission, the spacecraft's top priority is to record space radiation (known as cosmic rays) in order to refine its earlier measurements of the atomic species down to about a yard (meter) underground. The data Dawn has been collecting are excellent. [Image] Dawn saw this rugged terrain on August 15, 2016, from an altitude of 240 miles (385 kilometers). This is the southeastern end of a network of canyons in Yalode Crater called Nar Sulcus. (Nar is from a modern pomegranate feast in part of Azerbaijan. A sulcus is a set of parallel furrows or ridges.) We saw the rest of these canyons as they extend far to the northwest here. Geological structures like this have been found on some icy moons of the outer planets. The tremendous impact that formed Yalode heated the mixture of ice, rock and salt, which is a common combination on Ceres, perhaps causing a large volume to melt. When it subsequently refroze, it would have expanded (just as water does when it turns to ice in your freezer), and that may have created stresses that fractured the ground, forming Nar Sulcus. You can locate this scene in the eastern part of Yalode on this map near 41S, 281E. With a diameter of 162 miles (260 kilometers), Yalode is the second largest crater on Ceres. We have presented other photos of the crater, most recently in January. Full image and caption. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA As we explained in January, the ambitious mission has added a complex bonus to its plans. The team is piloting the ship through an intricate set of space maneuvers to dramatically shift its orbit around Ceres. They are now about halfway through, and it has been smooth sailing. Dawn is on course and on schedule. (If you happen to be one of the few readers for whom it isn't second nature to plan how to change a spacecraft's orbit around a dwarf planet by 90 degrees and then fly it under control of ion engine, last month's Dawn Journal presents a few of the details that may not be obvious. And you can follow the adventurer's orbital progress with the regular mission status updates.) If all goes well, on April 29 the new orbit will take Dawn exactly between the sun and the famous bright region at the center of Occator Crater. Named Cerealia Facula, the area is composed largely of salts. (Based on infrared spectra, the strongest candidate for the primary constituent is sodium carbonate). The probe will be at an altitude of about 12,400 miles (20,000 kilometers), or more than 50 times higher than it was in 2016 when it captured its sharpest photos of Occator (as well as the rest of Ceres' 1.1 million square miles, or 2.8 million square kilometers). But the objective of reaching a position at which the sun and Ceres are in opposite directions, a special alignment known as opposition, is not to take pictures that display more details to our eyes. In fact, however, the pictures will contain intriguing new details that are not readily discerned by visual inspection. Dawn will take pictures as it gets closer and closer to opposition, covering a range of angles. In each image, scientists will scrutinize the handful of pixels on Cerealia Facula to track how the brightness changes as Dawn's vantage point changes. [Occator Crater Image] Dawn took this photo of Occator Crater on Oct. 18, 2016, at an altitude of 920 miles (1,480 kilometers) in extended mission orbit 2. We have seen other views of Occator, from farther, from closer, with exposures optimized for the brightest areas, in color, with the crater on the limb of Ceres and more, but you can never have too many pictures of such a captivating scene. The central bright region is Cerealia Facula, and the collection of others is Vinalia Faculae. (A bright region on a planet is a facula. Here is more on these names.) These are the brightest areas on Ceres. One scenario for how they formed is that underground briny water made its way to the surface through fractures. When the water was on the ground, exposed to the cold vacuum of space, it froze and sublimated (that is, it transformed from a solid to a gas). The dissolved salt was left behind, with sodium carbonate being the likely principal constituent, and that reflective material is what we see here. We will see below that opposition surge measurements may provide evidence to support or modify this scenario. (A recent estimate is that Cerealia Facula may be some tens of millions of years younger than the crater itself. We discussed last year how ages are determined.) Since we can't have
[meteorite-list] Prolific Mars Orbiter Completes 50, 000 Orbits (MRO)
https://www.jpl.nasa.gov/news/news.php?feature=6800 Prolific Mars Orbiter Completes 50,000 Orbits Jet Propulsion Laboratory March 29, 2017 The most data-productive spacecraft yet at Mars swept past its 50,000th orbit this week, continuing to compile the most sharp-eyed global coverage ever accomplished by a camera at the Red Planet. In addition, the spacecraft -- NASA's Mars Reconnaissance Orbiter (MRO) -- recently aided preparations for NASA's next mission to Mars, the InSight lander. Insight will launch next year on a mission to study the planet's deep interior. Meanwhile, the orbiter continues diverse science observations of Mars and communications-relay service for two active Mars rovers, Curiosity and Opportunity. MRO's Context Camera (CTX) exploits a sweet spot in the balance between resolution and image file size. With a resolution of about 20 feet (6 meters) per pixel in images of the Martian surface, it has provided a library of images now covering 99.1 percent of Mars. That is approximately equivalent to the land area of Earth. No other camera ever sent to Mars has photographed so much of the planet in such high resolution. The Context Camera has taken about 90,000 images since the spacecraft began examining Mars from orbit in late 2006. Each one reveals shapes of features down to sizes smaller than a tennis court, in a swath of ground about 18.6 miles (30 kilometers) wide. "Reaching 99.1-percent coverage has been tricky because a number of factors, including weather conditions, coordination with other instruments, downlink limitations, and orbital constraints, tend to limit where we can image and when," said Context Camera Team Leader Michael Malin of Malin Space Science Systems, San Diego. In addition to observing nearly the entire planet at least once, the Context Camera has observed 60.4 percent of the planet more than once. These observations aid science directly and also certify the safety of future landing sites. Malin said, "Single coverage provides a baseline we can use for comparison with future observations, as we look for changes. Re-imaging areas serves two functions: looking for changes and acquiring stereoscopic views from which we can make topographic maps." A dramatic type of change the Context Camera has documented more than 200 times is a fresh impact crater appearing between the times of two observations. These images enabled scientists to calculate the rate at which small asteroids, or bits of comets, are colliding with Mars. Some of the fresh impacts reveal white material interpreted as water ice. The latitudes and estimated depths of the ice-exposing craters provide evidence about the distribution of buried ice near the surface. MRO's Shallow Radar has found ice farther underground, but this very shallow ice would go undetected if not for its exposure by impacts. One of MRO's other cameras, the High Resolution Imaging Science Experiment (HiRISE), can zoom in on the new impact craters found by the Context Camera. For some of these craters, HiRISE and MRO's Compact Reconnaissance Imaging Spectrometer for Mars have confirmed the presence of water ice. However, even though MRO has returned more than 300 terabits of science data, the much higher spatial resolution of HiRISE has limited its coverage of Mars' surface to about three percent. A third MRO camera, the Mars Color Imager, observes almost the entire planet every day to track weather change. Another instrument, the Mars Climate Sounder, records vertical profiles of the atmosphere's temperatures and suspended particles. The spacecraft was launched Aug. 12, 2005. It entered an elongated orbit of Mars in March 2006, then spent several months using friction with Mars' upper atmosphere to revise its orbit. Since beginning its science operations in November 2006, MRO has been flying near-polar orbits lasting about two hours, at altitudes from 155 to 196 miles (250 to 316 kilometers). The mission completed its 50,000th orbit on Monday, March 27. "After 11 and a half years in flight, the spacecraft is healthy and remains fully functional," said MRO Project Manager Dan Johnston at NASA's Jet Propulsion Laboratory, Pasadena, California. "It's a marvelous vehicle that we expect will serve the Mars Exploration Program and Mars science for many more years to come." On March 22, the mission made the latest adjustment to the orbit, with a 45.1-second burn of six intermediate-size rocket engines, each of which provides 5 pounds (22 newtons) of thrust. This maneuver revised the orbit orientation, so that the spacecraft can be at the right place at the right time, on Nov. 26, 2018, to receive critical radio transmissions from NASA's InSight Mars lander as it descends to the surface. MRO has already provided more than 60 images from HiRISE for advance analysis of the landing region for InSight. In a broad plain of the Elysium Planitia region of equatorial Mars,
[meteorite-list] NASA Selects CubeSat, SmallSat Mission Concept Studies
https://www.jpl.nasa.gov/news/news.php?feature=6791 NASA Selects CubeSat, SmallSat Mission Concept Studies Jet Propulsion Laboratory March 23, 2017 NASA has selected 10 studies under the Planetary Science Deep Space SmallSat Studies (PSDS3) program to develop mission concepts using small satellites to investigate Venus, Earth's moon, asteroids, Mars and the outer planets. For these studies, small satellites are defined as less than 180 kilograms in mass (about 400 pounds). CubeSats are built to standard specifications of 1 unit (U), which is equal to about 4x4x4 inches (10x10x10 centimeters). They often are launched into orbit as auxiliary payloads, significantly reducing costs. "These small but mighty satellites have the potential to enable transformational science," said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington. "They will provide valuable information to assist in planning future Announcements of Opportunity, and to guide NASA's development of small spacecraft technologies for deep space science investigation." NASA's Science Mission Directorate is developing a small satellite strategy, with the goal of identifying high-priority science objectives in each discipline that can be addressed with CubeSats and SmallSats, managed for appropriate cost and risk. This multi-disciplinary approach will leverage and partner with the growing commercial sector to collaboratively drive instrument and sensor innovation. The PSDS3 awardees were recognized this week at the 48th Lunar and Planetary Society Conference in The Woodlands, Texas. The total value of the awards is $3.6 million. The recipients are: Venus Christophe Sotin, NASA's Jet Propulsion Laboratory, Pasadena, California: Cupid's Arrow, a 66-pound (30-kilogram) probe to measure noble gases and their isotopes to investigate the geological evolution of Venus and why Venus and Earth have evolved so differently. Valeria Cottini, University of Maryland, College Park: CubeSat UV Experiment (CUVE), a 12-unit CubeSat orbiter to measure ultraviolet absorption and nightglow emissions to understand Venus' atmospheric dynamics. Moon Suzanne Romaine, Smithsonian Astrophysical Observatory, Cambridge, Massachusetts: CubeSat X-ray Telescope (CubeX), a 12-unit CubeSat to map the elemental composition mapping of airless bodies such as the moon, to understand their formation and evolutionary history using X-ray pulsar timing for deep space navigation. Timothy Stubbs, NASA Goddard Space Flight Center, Greenbelt, Maryland: Bi-sat Observations of the Lunar Atmosphere above Swirls (BOLAS), tethered 12-unit CubeSats to investigate the lunar hydrogen cycle by simultaneously measuring electromagnetic fields near the surface of the moon, and incoming solar winds high above. Asteroids Jeffrey Plescia, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland: Asteroid Probe Experiment (APEX), a SmallSat with a deployable seismometer to rendezvous with the asteroid Apophis and directly explore its interior structure, surface properties, and rotational state. Benton Clark, Lockheed Martin Space Systems Company, Littleton, Colorado: CubeSat Asteroid Encounters for Science and Reconnaissance (CAESAR), a constellation of 6-unit CubeSats to evaluate the bulk properties of asteroids to assess their physical structure, and to provide constraints on their formation and evolution. Mars David Minton, Purdue University, West Lafayette, Indiana: Chariot to the Moons of Mars, a 12-unit CubeSat with a deployable drag skirt to produce high-resolution imagery and surface material composition of Phobos and Deimos, to help understand how they were formed. Anthony Colaprete, NASA Ames Research Center, Moffett Field, California: Aeolus, a 24-unit CubeSat to directly measure vertically-resolved global winds to help determine the global energy balance at Mars and understand daily climate variability. Icy Bodies and Outer Planets Kunio Sayanagi, Hampton University, Virginia: Small Next-generation Atmospheric Probe (SNAP), an atmospheric entry probe to measure vertical cloud structure, stratification, and winds to help understand the chemical and physical processes that shape the atmosphere of Uranus. Robert Ebert, Southwest Research Institute, San Antonio: JUpiter MagnetosPheric boundary ExploreR (JUMPER), a SmallSat to explore Jupiter's magnetosphere, including characterizing the solar wind upstream of the magnetosphere to provide science context for future missions such as the Europa Clipper. For more information about NASA's CubeSat activities, visit: https://www.nasa.gov/mission_pages/cubesats/index.html News Media Contact Andrew Good Jet Propulsion Laboratory, Pasadena, Calif. 818-393-2433 andrew.c.g...@jpl.nasa.gov 2017-085 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at
[meteorite-list] Ice in Ceres' Shadowed Craters Linked to Tilt History
https://www.jpl.nasa.gov/news/news.php?feature=6787 Ice in Ceres' Shadowed Craters Linked to Tilt History Jet Propulsion Laboratory March 22, 2017 Dwarf planet Ceres may be hundreds of millions of miles from Jupiter, and even farther from Saturn, but the tremendous influence of gravity from these gas giants has an appreciable effect on Ceres' orientation. In a new study, researchers from NASA's Dawn mission calculate that the axial tilt of Ceres -- the angle at which it spins as it journeys around the sun -- varies widely over the course of about 24,500 years. Astronomers consider this to be a surprisingly short period of time for such dramatic deviations. Changes in axial tilt, or "obliquity," over the history of Ceres are related to the larger question of where frozen water can be found on Ceres' surface, scientists report in the journal Geophysical Research Letters. Given conditions on Ceres, ice would only be able to survive at extremely cold temperatures -- for example, in areas that never see the sun. "We found a correlation between craters that stay in shadow at maximum obliquity, and bright deposits that are likely water ice," said Anton Ermakov, postdoctoral researcher at NASA's Jet Propulsion Laboratory, Pasadena, California, and lead author of the study. "Regions that never see sunlight over millions of years are more likely to have these deposits." Cycles of Obliquity Throughout the last 3 million years, Ceres has gone through cycles where its tilt ranges from about 2 degrees to about 20 degrees, calculations indicate. "We cannot directly observe the changes in Ceres' orientation over time, so we used the Dawn spacecraft's measurements of shape and gravity to precisely reconstruct what turned out to be a dynamic history," said Erwan Mazarico, a co-author at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The last time the dwarf planet reached a maximum tilt, which was about 19 degrees, was 14,000 years ago, researchers said. For comparison, Earth is tilted 23.5 degrees. This significant tilt causes our planet to experience seasons: The northern hemisphere experiences summer when it is oriented toward the sun, and winter when it's pointed away from the sun. By contrast, Ceres' current tilt is about 4 degrees, so it will not have such strong seasonal effects over the course of a year there (which is about 4.6 Earth years). How Obliquity Relates to Ice When the axial tilt is small, relatively large regions on Ceres never receive direct sunlight, particularly at the poles. These persistently shadowed regions occupy an area of about 800 square miles (2,000 square kilometers). But when the obliquity increases, more of the craters in the polar regions receive direct exposure to the sun, and persistently shadowed areas only occupy 0.4 to 4 square miles (1 to 10 square kilometers). These areas on Ceres' surface, which stay in shadow even at high obliquity, may be cold enough to maintain surface ice, Dawn scientists said. These craters with areas that stay in shadow over long periods of time are called "cold traps," because they are so cold and dark that volatiles -- substances easily vaporized -- that migrate into these areas can't escape, even over a billion years. A 2016 study by the Dawn team in Nature Astronomy found bright material in 10 of these craters, and data from Dawn's visible and infrared mapping spectrometer indicate that one of them contains ice. The new study focused on polar craters and modeled how shadowing progresses as Ceres' axial tilt varies. In the northern hemisphere, only two persistently shadowed regions remain in shadow at the maximum 20-degree tilt. Both of these regions have bright deposits today. In the southern hemisphere, there are also two persistently shadowed regions at highest obliquity, and one of them clearly has a bright deposit. Shadowed Regions in Context Ceres is the third body in the solar system found to have permanently shadowed regions. Mercury and Earth's moon are the other two, and scientists believe they received their ice from impacting bodies. However, Mercury and the moon do not have such wide variability in their tilts because of the stabilizing gravitational influence of the sun and Earth, respectively. The origin of the ice in Ceres' cold traps is more mysterious -- it may come from Ceres itself, or may be delivered by impacts from asteroids and comets. Regardless, the presence of ice in cold traps could be related to a tenuous water atmosphere, which was detected by ESA's Herschel Space Observatory in 2012-13. Water molecules that leave the surface would fall back onto Ceres, with some landing in cold traps and accumulating there. "The idea that ice could survive on Ceres for long periods of time is important as we continue to reconstruct the dwarf planet's geological history, including whether it has been giving off water vapor," said Carol Raymond, deputy
[meteorite-list] The Many Faces of Rosetta's Comet 67P
https://www.jpl.nasa.gov/news/news.php?feature=6786 The Many Faces of Rosetta's Comet 67P Jet Propulsion Laboratory March 21, 2017 Images returned from the European Space Agency's Rosetta mission indicate that during its most recent trip through the inner solar system, the surface of comet 67P/Churyumov-Gerasimenko was a very active place - full of growing fractures, collapsing cliffs and massive rolling boulders. Moving material buried some features on the comet's surface while exhuming others. A study on 67P's changing surface was released Tuesday, March 21, in the journal Science. "As comets approach the sun, they go into overdrive and exhibit spectacular changes on their surface," said Ramy El-Maarry, study leader and a member of the U.S. Rosetta science team from the University of Colorado, Boulder. "This is something we were not able to really appreciate before the Rosetta mission, which gave us the chance to look at a comet in ultra-high resolution for more than two years." Most comets orbit our sun in highly elliptical orbits that cause them to spend most of their time in the extremely cold outer solar system. When a comet approaches the inner solar system, the sun begins to warm the ice on and near the comet's surface. When the ice warms enough it can rapidly sublimate (turn directly from the solid to the vapor state). This sublimation process can occur with variable degrees of intensity and time-scales and cause the surface to change rapidly. Between August 2014 and September 2016, Rosetta orbited comet 67P during the comet's swing through the inner-solar system. "We saw a massive cliff collapse and a large crack in the neck of the comet get bigger and bigger," said El-Maarry. "And we discovered that boulders the size of a large truck could be moved across the comet's surface a distance as long as one-and-a-half football fields." In the case of the boulder, Rosetta's cameras observed a 282-million-pound (130-million-kilogram), 100-feet-wide (30-meter) space rock to have moved 150 yards (460 feet, or 140 meters) from its original position on the comet's nucleus. The massive space rock probably moved as a result of several outburst events that were detected close to its original position. The warming of 67P also caused the comet's rotation rate to speed up. The comet's increasing spin rate in the lead-up to perihelion is thought to be responsible for a 1,600-foot-long (500-meters) fracture spotted in August 2014 that runs through the comet's neck. The fracture, which originally extended a bit longer than the Empire State Building is high, was found to have increased in width by about 100 feet (30 meters) by December 2014. Furthermore, in images taken in June 2016, a new 500- to 1,000-foot-long (150 to 300 meters) fracture was identified parallel to the original fracture. "The large crack was in the 'neck' of the comet -- a small central part that connects the two lobes," said El-Maarry. "The crack was extending--indicating that the comet may split up one day." Understanding how comets change and evolve with time gives us important insights into the types and abundance of ices in comets, and how long comets can stay in the inner solar system before losing all their ice and becoming balls of dust," said El-Maarry. "This helps us better understand the conditions of the early solar system, and possibly even how life started." A link to an ESA press release with more information on the El-Maarry paper in Science can be found here: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Before_and_after_unique_changes_spotted_on_Rosetta_s_comet In a second Rosetta study released Tuesday, this one published in Nature Astronomy, scientists make the first definitive link between an outburst of dust and gas from the nucleus of 67P and the collapse of one of its prominent cliffs, which also exposed the comet's pristine, icy interior. A link to an ESA press release on the Nature Astronomy paper can be found here: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Collapsing_cliff_reveals_comet_s_interior Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta was the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and whether comets brought life-sustaining water and organic molecules to the Earth. Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae lander is provided by a consortium led by the German Aerospace Center, Cologne; Max Planck Institute for Solar System Research, Gottingen; French National Space Agency, Paris; and the Italian Space Agency, Rome. JPL, Pasadena, California, a division of Caltech in Pasadena, manages the U.S.
[meteorite-list] Breaks Observed in Mars Curiosity Rover Wheel Treads
https://www.jpl.nasa.gov/news/news.php?feature=6785 Breaks Observed in Rover Wheel Treads Jet Propulsion Laboratory March 21, 2017 Mars Science Laboratory Mission Status Report A routine check of the aluminum wheels on NASA's Curiosity Mars rover has found two small breaks on the rover's left middle wheel-the latest sign of wear and tear as the rover continues its journey, now approaching the 10-mile (16 kilometer) mark. The mission's first and second breaks in raised treads, called grousers, appeared in a March 19 image check of the wheels, documenting that these breaks occurred after the last check, on Jan. 27. "All six wheels have more than enough working lifespan remaining to get the vehicle to all destinations planned for the mission," said Curiosity Project Manager Jim Erickson at NASA's Jet Propulsion Laboratory, Pasadena, California. "While not unexpected, this damage is the first sign that the left middle wheel is nearing a wheel-wear milestone," The monitoring of wheel damage on Curiosity, plus a program of wheel-longevity testing on Earth, was initiated after dents and holes in the wheels were seen to be accumulating faster than anticipated in 2013. Testing showed that at the point when three grousers on a wheel have broken, that wheel has reached about 60 percent of its useful life. Curiosity already has driven well over that fraction of the total distance needed for reaching the key regions of scientific interest on Mars' Mount Sharp. Curiosity Project Scientist Ashwin Vasavada, also at JPL, said, "This is an expected part of the life cycle of the wheels and at this point does not change our current science plans or diminish our chances of studying key transitions in mineralogy higher on Mount Sharp." Curiosity is currently examining sand dunes partway up a geological unit called the Murray formation. Planned destinations ahead include the hematite-containing "Vera Rubin Ridge," a clay-containing geological unit above that ridge, and a sulfate-containing unit above the clay unit. The rover is climbing to sequentially higher and younger layers of lower Mount Sharp to investigate how the region's ancient climate changed billions of years ago. Clues about environmental conditions are recorded in the rock layers. During its first year on Mars, the mission succeeded at its main goal by finding that the region once offered environmental conditions favorable for microbial life, if Mars has ever hosted life. The conditions in long-lived ancient freshwater Martian lake environments included all of the key chemical elements needed for life as we know it, plus a chemical source of energy that is used by many microbes on Earth. Through March 20, Curiosity has driven 9.9 miles (16.0 kilometers) since the mission's August 2012 landing on Mars. Studying the transition to the sulfate unit, the farthest-uphill destination, will require about 3.7 miles (6 kilometers) or less of additional driving. For the past four years, rover drive planners have used enhanced methods of mapping potentially hazardous terrains to reduce the pace of damage from sharp, embedded rocks along the rover's route. Each of Curiosity's six wheels is about 20 inches (50 centimeters) in diameter and 16 inches (40 centimeters) wide, milled out of solid aluminum. The wheels contact ground with a skin that's about half as thick as a U.S. dime, except at thicker treads. The grousers are 19 zigzag-shaped treads that extend about a quarter inch (three-fourths of a centimeter) outward from the skin of each wheel. The grousers bear much of the rover's weight and provide most of the traction and ability to traverse over uneven terrain. JPL, a division of Caltech in Pasadena, California, manages NASA's Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington, and built the project's rover, Curiosity. For more information about the mission, visit: http://mars.jpl.nasa.gov/msl/ News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov 2017-079 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Origami-inspired Robot Can Hitch a Ride with a Rover
https://www.jpl.nasa.gov/news/news.php?feature=6782 Origami-inspired Robot Can Hitch a Ride with a Rover Jet Propulsion Laboratory March 20, 2017 The next rovers to explore another planet might bring along a scout. The Pop-Up Flat Folding Explorer Robot (PUFFER) in development at NASA's Jet Propulsion Laboratory in Pasadena, California, was inspired by origami. Its lightweight design is capable of flattening itself, tucking in its wheels and crawling into places rovers can't fit. Over the past year and a half, PUFFER has been tested in a range of rugged terrains, from the Mojave Desert in California to the snowy hills of Antarctica. The idea is to explore areas that might be too risky for a full-fledged rover to go, such as steep slopes or behind sand dunes. It's designed to skitter up 45-degree slopes, investigate overhangs and even drop into pits or craters. PUFFER is meant to be the hardy assistant to a larger robot companion: several of the microbots can be flattened like cards and stacked one on top of the other. Then, they can be flicked out, popped up and begin exploring. "They can do parallel science with a rover, so you can increase the amount you're doing in a day," said Jaakko Karras, PUFFER's project manager at JPL. "We can see these being used in hard-to-reach locations -- squeezing under ledges, for example." PUFFER's creators at JPL hope to see the bot rolling across the sands of Mars someday. But they imagine it could be used by scientists right here on Earth, as well. Carolyn Parcheta, a JPL scientist who uses robots to explore volcanoes, offered guidance on PUFFER's science instruments. She said the use of backpack-ready bots has enormous potential for fields like geology. "Having something that's as portable as a compass or a rock hammer means you can do science on the fly," she said. A paper prototype PUFFER's body was originated by Karras, who was experimenting with origami designs. While he was a grad student at UC Berkeley's Biomimetic Millisystem Lab, he worked on developing robotics based on natural forms, like animal and insect movement. The PUFFER team substituted paper with a printed circuit board -- the same thing inside of your smartphone. That allowed them to incorporate more electronics, including control and rudimentary instruments. "The circuit board includes both the electronics and the body, which allows it to be a lot more compact," said Christine Fuller, a JPL mechanical engineer who worked on PUFFER's structure and tested it for reliability. "There are no mounting fasteners or other parts to deal with. Everything is integrated to begin with." JPL's Kalind Carpenter, who specializes in robotic mobility, made four wheels for the folding bot on a 3-D printer. Their first prototype was little more than rolling origami, but it quickly grew more complex. The wheels evolved, going from four to two, and gaining treads that allow it to climb inclines. They can also be folded over the main body, allowing PUFFER to crawl. A tail was added for stabilization. Solar panels on PUFFER's belly allow it to flip over and recharge in the sun. The team partnered with the Biomimetic Millisystems Lab, which developed a "skittering walk" that keeps the bot inching forward, one wheel at a time, without slipping. A company called Distant Focus Corporation, Champaign, Illinois, provided a high-resolution microimager sensitive enough to see objects that are just 10 microns in size -- a fraction of a diameter of a human hair. Before long, PUFFER was ready for a test drive. >From the Mojave to Mars Once they had a functional prototype, the JPL team took PUFFER out for field testing. In Rainbow Basin, California, the bot clambered over sedimentary rock slopes and under overhangs. That terrain serves as an analog to Martian landscapes. On Mars, overhangs could be sheltering organic molecules from harmful radiation. Darkly colored Martian slopes, which are of interest to scientists, are another potential target. On a level dirt path, PUFFER can drive about 2,050 feet (625 meters) on one battery charge. That could fluctuate a bit depending on how much any onboard instruments are used. Besides desert conditions, PUFFER has been outfitted for snow. Carpenter designed bigger wheels and a flat fishtail to help it traverse wintry terrain. So far, it's been tested at a ski resort in Grand Junction, Colorado; Big Bear, California; and on Mt. Erebus, an active volcano in Antarctica. One of PUFFER's more recent field tests wasn't particularly challenging, but can still be counted as a success: the Consumer Electronics Show. On a convention center floor in Las Vegas, it drew crowds of delighted technology fans. PUFFER grows up The next step is making PUFFER a scientist. The JPL team is looking at adding a number of instruments that would allow it to sample water for organic material, or a spectrometer to study the chemical makeup of
[meteorite-list] COBALT Flight Demonstrations Fuse Technologies to Gain Precision Landing Results
https://www.jpl.nasa.gov/news/news.php?feature=6780 COBALT Flight Demonstrations Fuse Technologies to Gain Precision Landing Results March 17, 2017 Many regions in the solar system beckon for exploration, but they are considered unreachable due to technology gaps in current landing systems. The CoOperative Blending of Autonomous Landing Technologies (COBALT) project, conducted by NASA's Space Technology Mission Directorate (STMD) and Human Exploration and Operations Mission Directorate, could change that. Through a flight campaign this month through April, COBALT will mature and demonstrate new guidance, navigation and control (GN) technologies to enable precision landing for future exploration missions. "COBALT will allow us to reduce the risk in developing future landing systems and will benefit robotic landers to planetary surfaces by allowing for autonomous precision landing," said LaNetra Tate, STMD's Game Changing Development (GCD) program executive. "This will definitely become a game-changing technology." The campaign will pair and test new landing sensor technologies that promise to yield the highest-precision navigation solution ever tested for NASA space landing applications. The technologies, a Navigation Doppler Lidar (NDL), which provides ultra-precise velocity and line-of-sight range measurements, and the Lander Vision System (LVS), which provides terrain relative navigation, will be integrated and flight tested aboard a rocket-powered vertical takeoff, vertical landing (VTVL) platform. The platform, named Xodiac, was developed by Masten Space Systems in Mojave, California. "In this first flight campaign, we plan to successfully complete the integration, flight testing and performance analysis of the COBALT payload," explained John M. Carson III, COBALT project manager. "This is considered a passive test, where COBALT will be solely collecting data, while the Xodiac vehicle will rely on its GPS for active navigation."" In a follow-up flight campaign in summer 2017, COBALT will become the active navigation system for Xodiac, and the vehicle will use GPS only as a safety monitor and backup. "The knowledge from these flights will lead into the development of systems for deployment in future NASA landing missions to Mars and the moon," said Carson. So how does it work? The technologies themselves are very different, but together they are a recipe for precision landing. The NDL, developed at NASA's Langley Research Center (LaRC), is an evolution of a prototype flown by the former ALHAT (Autonomous precision Landing and Hazard Avoidance Technology) project on the NASA Morpheus vehicle in 2014. The new NDL is 60 percent smaller, operates at nearly triple the speed and provides longer range measurements. "NDL functionally is similar to the radar systems used in previous Mars landers, Phoenix and Mars Science Laboratory," explained Farzin Amzajerdian, NDL chief scientist at Langley. "The major difference is that the NDL uses a laser instead of a microwave as its transmitter. Operating at almost four orders of magnitude higher frequency makes the measurement a whole lot more accurate. NDL also is much smaller than radar systems, which is a big deal as every ounce counts when sending a lander to Mars or other destinations." LVS, developed at NASA's Jet Propulsion Laboratory, is a camera-based navigation system that photographs the terrain beneath a descending spacecraft and matches it with onboard maps to determine vehicle location, explained Carl Seubert, the COBALT project lead at JPL. "This allows the craft to detect its location relative to large landing hazards seen in the onboard maps, such as large boulders and terrain outcroppings," Seubert said. COBALT is one springboard for these technologies, which will find their way into future missions. The NDL design is geared toward infusion onto near-term lunar, Mars or other missions. The LVS was developed for infusion onto the Mars 2020 robotic lander mission, and has application to many other missions. "Both NDL and LVS come from more than a decade of NASA research and development investments across multiple projects within robotic and human exploration programs, and from the hard work and dedication of personnel across the agency," said Carson. "These COBALT technologies give moon and Mars spacecraft the ability to land much more precisely, improving access to interesting sites in complex terrain and to any exploration assets previously deployed to the surface," said Jason Crusan, director of NASA's Advanced Exploration Systems division. "Landings will also be more controlled and gentle, potentially allowing smaller landing legs and propellant reserves, and resulting in lower mission risk, mass and cost." The COBALT team is managed at NASA's Johnson Space Center (JSC) in Houston, and comprises of engineers from JSC, JPL in Pasadena, California, and LaRC in Hampton,
[meteorite-list] Dawn Identifies Age of Ceres' Brightest Area
https://www.jpl.nasa.gov/news/news.php?feature=6766 Dawn Identifies Age of Ceres' Brightest Area Jet Propulsion Laboratory March 8, 2017 The bright central area of Ceres' Occator Crater, known as Cerealia Facula, is approximately 30 million years younger than the crater in which it lies, according to a new study in the Astronomical Journal. Scientists used data from NASA's Dawn spacecraft to analyze Occator's central dome in detail, concluding that this intriguing bright feature on the dwarf planet is only about 4 million years old -- quite recent in terms of geological history. Researchers led by Andreas Nathues at the Max Planck Institute for Solar System Research (MPS) in Gottingen, Germany, analyzed data from two instruments on board NASA's Dawn spacecraft: the framing camera, and the visible and infrared mapping spectrometer. The new study supports earlier interpretations from the Dawn team that this reflective material -- comprising the brightest area on all of Ceres -- is made of carbonate salts, although it did not confirm a particular type of carbonate previously identified. The secondary, smaller bright areas of Occator, called Vinalia Faculae, are comprised of a mixture of carbonates and dark material, the study authors wrote. New evidence also suggests that Occator's bright dome likely rose in a process that took place over a long period of time, rather than forming in a single event. They believe the initial trigger was the impact that dug out the crater itself, causing briny liquid to rise closer to the surface. Water and dissolved gases, such as carbon dioxide and methane, came up and created a vent system. These rising gases also could have forced carbonate-rich materials to ascend toward the surface. During this period, the bright material would have erupted through fractures, eventually forming the dome that we see today. Read more from MPS The spacecraft is currently on its way to a high-altitude orbit of 12,400 miles (20,000 kilometers), and to a different orbital plane. In late spring, Dawn will view Ceres in "opposition," with the sun directly behind the spacecraft. By measuring details of the brightness of the salt deposits in this new geometry, scientists may gain even more insights into these captivating bright areas. The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: http://dawn.jpl.nasa.gov/mission More information about Dawn is available at the following sites: http://www.nasa.gov/dawn http://dawn.jpl.nasa.gov News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6425 elizabeth.lan...@jpl.nasa.gov 2017-059 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Does Mars Have Rings? Not Right Now, But Maybe One Day
https://www.jpl.nasa.gov/news/news.php?feature=6781 Does Mars Have Rings? Not Right Now, But Maybe One Day Jet Propulsion Laboratory March 20, 2017 As children, we learned about our solar system's planets by certain characteristics -- Jupiter is the largest, Saturn has rings, Mercury is closest to the sun. Mars is red, but it's possible that one of our closest neighbors also had rings at one point and may have them again someday. That's the theory put forth by NASA-funded scientists at Purdue University, Lafayette, Indiana, whose findings were published in the journal Nature Geoscience. David Minton and Andrew Hesselbrock developed a model that suggests that debris that was pushed into space from an asteroid or other body slamming into Mars around 4.3 billion years ago alternates between becoming a planetary ring and clumping together to form a moon. One theory suggests that Mars' large North Polar Basin or Borealis Basin -- which covers about 40 percent of the planet in its northern hemisphere -- was created by that impact, sending debris into space. "That large impact would have blasted enough material off the surface of Mars to form a ring," Hesselbrock said. Hesselbrock and Minton's model suggests that as the ring formed, and the debris slowly moved away from the Red Planet and spread out, it began to clump and eventually formed a moon. Over time, Mars' gravitational pull would have pulled that moon toward the planet until it reached the Roche limit, the distance within which a planet's tidal forces will break apart a celestial body that is held together only by gravity. Phobos, one of Mars' moons, is getting closer to the planet. According to the model, Phobos will break apart upon reaching the Roche limit, and become a set of rings in roughly 70 million years. Depending on where the Roche limit is, Minton and Hesselbrock believe this cycle may have repeated between three and seven times over billions of years. Each time a moon broke apart and reformed from the resulting ring, its successor moon would be five times smaller than the last, according to the model, and debris would have rained down on the planet, possibly explaining enigmatic sedimentary deposits found near Mars' equator. "You could have had kilometer-thick piles of moon sediment raining down on Mars in the early parts of the planet's history, and there are enigmatic sedimentary deposits on Mars with no explanation as to how they got there," Minton said. "And now it's possible to study that material." Other theories suggest that the impact with Mars that created the North Polar Basin led to the formation of Phobos 4.3 billion years ago, but Minton said it's unlikely the moon could have lasted all that time. Also, Phobos would have had to form far from Mars and would have had to cross through the resonance of Deimos, the outer of Mars' two moons. Resonance occurs when two moons exert gravitational influence on each other in a repeated periodic basis, as major moons of Jupiter do. By passing through its resonance, Phobos would have altered Deimos' orbit. But Deimos' orbit is within one degree of Mars' equator, suggesting Phobos has had no effect on Deimos. "Not much has happened to Deimos' orbit since it formed," Minton said. "Phobos passing through these resonances would have changed that." "This research highlights even more ways that major impacts can affect a planetary body," said Richard Zurek of NASA's Jet Propulsion Laboratory, Pasadena, California. He is the project scientist for NASA's Mars Reconnaissance Orbiter, whose gravity mapping provided support for the hypothesis that the northern lowlands were formed by a massive impact. Minton and Hesselbrock will now focus their work on either the dynamics of the first set of rings that formed or the materials that have rained down on Mars from disintegration of moons. For more information about NASA missions investigating Mars, visit: https://mars.nasa.gov/ News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov Steve Tally / Emil Venere Purdue University, West Lafayette, Ind. 765-494-9809 / 765-494-4709 st...@purdue.edu / ven...@purdue.edu Writer: Brian Wallheimer 2017-075 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Mars Orbiter Tracks Back-to-Back Regional Storms (MRO)
https://www.jpl.nasa.gov/news/news.php?feature=6771 NASA Mars Orbiter Tracks Back-to-Back Regional Storms Jet Propulsion Laboratory March 9, 2017 A regional dust storm currently swelling on Mars follows unusually closely on one that blossomed less than two weeks earlier and is now dissipating, as seen in daily global weather monitoring by NASA's Mars Reconnaissance Orbiter. Images from the orbiter's wide-angle Mars Color Imager (MARCI) show each storm growing in the Acidalia area of northern Mars, then blowing southward and exploding to sizes bigger than the United States after reaching the southern hemisphere. That development path is a common pattern for generating regional dust storms during spring and summer in Mars' southern hemisphere, where it is now mid-summer. "What's unusual is we're seeing a second one so soon after the first one," said Mars meteorologist Bruce Cantor of Malin Space Science Systems, San Diego, which built and operates MARCI. "We've had orbiters watching weather patterns on Mars continuously for nearly two decades now, and many patterns are getting predictable, but just when we think we have Mars figured out, it throws us another surprise." Weekly Martian weather reports including animated sequences of MARCI observations are available at: http://www.msss.com/msss_images/latest_weather.html Weather updates from the Mars Reconnaissance Orbiter science team provide operators of Mars rovers advance notice both for taking precautions and for planning observations of storms, particularly in case a regional storm grows to encircle the whole planet. A planet-encircling Martian storm last occurred in 2007. The orbiter monitors storms with its Mars Climate Sounder (MCS) instrument as well as with MARCI. MCS measurements of high-altitude atmospheric warming associated with dust storms have revealed an annual pattern in the occurrence of large regional storms, and the first of these back-to-back storms fits into the identified pattern for this time of the Martian year. Researchers have watched effects of the latest storms closely. "We hope for a chance to learn more about how dust storms become global, if that were to happen," said David Kass of NASA's Jet Propulsion Laboratory, Pasadena, California. "Even if it does not become a global storm, the temperature effects due to thin dust hazes will last for several weeks." Cantor reported the second of the current back-to-back regional storms on March 5 to the team operating NASA's Mars Exploration Rover Opportunity. The earlier storm, which had become regional in late February, was dissipating by then but still causing high-altitude haziness and warming. "There's still a chance the second one could become a planet-encircling storm, but it's unlikely because we're getting so late in the season," Cantor said this week. All previously observed planet-encircling dust storms on Mars occurred earlier in the southern summer. Opportunity Project Manager John Callas, at JPL, credits MARCI weather reports with helping his team protect rovers when sudden increases in atmospheric dust decrease sunlight reaching the rover solar arrays. For example, Cantor's warning about a regional storm approaching the rover Spirit in November 2008 prompted JPL to send an emergency weekend command to conserve energy by deleting a planned radio transmission by Spirit. That saved enough charge in Spirit's batteries to prevent "what would likely have been a very serious situation," Callas said. During the most recent global dust storm on Mars, in 2007, both of the rovers then operating on the planet -- Spirit and Opportunity -- were put into a power-saving mode for more than a week with minimal communication. The early-2010 ending of Spirit's mission was not related to a dust storm. The same winds that raise Martian dust into the atmosphere can clear some of the dust that accumulates on the rovers. On Feb. 25, as the first back-to-back was spreading regionally, Opportunity experienced a significant cleaning of its solar panels that increased their energy output by more than 10 percent, adjusted for the clarity of the atmosphere. Dust-removing events typically clean the panels by only one or two percent. The Opportunity operations team has noticed over the years that a large dust-cleaning event often precedes dusty skies. Since Feb. 25, the atmosphere over Opportunity has become dustier, and some of the dust has already fallen back onto the solar panels. "Before the first regional dust storm, the solar panels were cleaner than they were during the last four Martian summers, so the panels generated more energy," said JPL rover-power engineer Jennifer Herman. "It remains to be seen whether the outcome of these storms will be a cleaner or dirtier Opportunity. We have seen both results from dust storms in the past." NASA's Curiosity rover, on Mars since 2012, uses a radioisotope thermoelectric generator
[meteorite-list] Mars Volcano, Earth's Dinosaurs Went Extinct About the Same Time
https://www.jpl.nasa.gov/news/news.php?feature=6783 Mars Volcano, Earth's Dinosaurs Went Extinct About the Same Time Jet Propulsion Laboratory March 20, 2017 New NASA research reveals that the giant Martian volcano Arsia Mons produced one new lava flow at its summit every 1 to 3 million years during the final peak of activity. The last volcanic activity there ceased about 50 million years ago -- around the time of Earth's Cretaceous-Paleogene extinction, when large numbers of our planet's plant and animal species (including dinosaurs) went extinct. Located just south of Mars' equator, Arsia Mons is the southernmost member of a trio of broad, gently sloping shield volcanoes collectively known as Tharsis Montes. Arsia Mons was built up over billions of years, though the details of its lifecycle are still being worked out. The most recent volcanic activity is thought to have taken place in the caldera-the bowl-shaped depression at the top -- where 29 volcanic vents have been identified. Until now, it's been difficult to make a precise estimate of when this volcanic field was active. "We estimate that the peak activity for the volcanic field at the summit of Arsia Mons probably occurred approximately 150 million years ago -- the late Jurassic period on Earth -- and then died out around the same time as Earth's dinosaurs," said Jacob Richardson, a postdoctoral researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "It's possible, though, that the last volcanic vent or two might have been active in the past 50 million years, which is very recent in geological terms." Richardson is presenting the findings on March 20, 2017, at the Lunar and Planetary Science Conference in The Woodlands, Texas. The study also is published in Earth and Planetary Science Letters. Measuring about 68 miles (110 kilometers) across, the caldera is deep enough to hold the entire volume of water in Lake Huron, and then some. Examining the volcanic features within the caldera required high-resolution imaging, which the researchers obtained from the Context Camera on NASA's Mars Reconnaissance Orbiter. The team mapped the boundaries of the lava flows from each of the 29 volcanic vents and determined the stratigraphy, or layering, of the flows. The researchers also performed a technique called crater counting -- tallying up the number of craters at least 330 feet (100 meters) in diameter -- to estimate the ages of the flows. Using a new computer model developed by Richardson and his colleagues at the University of South Florida, the two types of information were combined to determine the volcanic equivalent of a batting order for Arsia Mons' 29 vents. The oldest flows date back about 200 million years. The youngest flows probably occurred 10 to 90 million years ago -- most likely around 50 million years ago. The modeling also yielded estimates of the volume flux for each lava flow. At their peak about 150 million years ago, the vents in the Arsia Mons' caldera probably collectively produced about 0.25 to 2 cubic miles (1 to 8 cubic kilometers) of magma every million years, slowly adding to the volcano's size. "Think of it like a slow, leaky faucet of magma," said Richardson. "Arsia Mons was creating about one volcanic vent every 1 to 3 million years at the peak, compared to one every 10,000 years or so in similar regions on Earth." A better understanding of when volcanic activity on Mars took place is important because it helps researchers understand the Red Planet's history and interior structure. "A major goal of the Mars volcanology community is to understand the anatomy and lifecycle of the planet's volcanoes. Mars' volcanoes show evidence for activity over a larger time span than those on Earth, but their histories of magma production might be quite different," said Jacob Bleacher, a planetary geologist at Goddard and a co-author on the study. "This study gives us another clue about how activity at Arsia Mons tailed off and the huge volcano became quiet." Malin Space Science Systems, San Diego, built and operates the Context Camera. NASA's Jet Propulsion Laboratory, Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. For more information about NASA missions investigating Mars, visit: https://mars.nasa.gov/ News Media Contact Elizabeth Zubritsky Goddard Space Flight Center, Greenbelt, Md. 301-614-5438 elizabeth.a.zubrit...@nasa.gov Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-076 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list
[meteorite-list] Cassini Reveals Strange Shape of Saturn's Moon Pan
https://www.jpl.nasa.gov/news/news.php?feature=6770 Cassini Reveals Strange Shape of Saturn's Moon Pan Jet Propulsion Laboratory March 9, 2017 [Images] These raw, unprocessed images of Saturn's tiny moon, Pan, were taken on March 7, 2017, by NASA's Cassini spacecraft. The flyby had a close-approach distance of 24,572 kilometers (15,268 miles). These images are the closest images ever taken of Pan and will help to characterize its shape and geology. Additional raw images from Cassini are available at: https://saturn.jpl.nasa.gov/galleries/raw-images The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency's Science Mission Directorate in Washington. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado. Caltech in Pasadena manages JPL for NASA. For more information about Cassini, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov News Media Contact Preston Dyches Jet Propulsion Laboratory, Pasadena, Calif. 818-354-7013 preston.dyc...@jpl.nasa.gov 2017-063 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] MAVEN Orbiter Steers Clear of Mars Moon Phobos
https://www.jpl.nasa.gov/news/news.php?feature=6764 NASA Orbiter Steers Clear of Mars Moon Phobos Jet Propulsion Laboratory March 2, 2017 NASA's MAVEN spacecraft performed a previously unscheduled maneuver this week to avoid a collision in the near future with Mars' moon Phobos. The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been orbiting Mars for just over two years, studying the Red Planet's upper atmosphere, ionosphere and interactions with the sun and solar wind. On Tuesday, Feb. 28, the spacecraft carried out a rocket motor burn that boosted its velocity by 0.4 meters per second (less than 1 mile per hour). Although a small correction, it was enough that -- projected to one week later when the collision would otherwise have occurred -- MAVEN would miss the lumpy, crater-filled moon by about 2.5 minutes. This is the first collision avoidance maneuver that the MAVEN spacecraft has performed at Mars to steer clear of Phobos. The orbits of both MAVEN and Phobos are known well enough that this timing difference ensures that they will not collide. MAVEN, with an elliptical orbit around Mars, has an orbit that crosses those of other spacecraft and the moon Phobos many times over the course of a year. When the orbits cross, the objects have the possibility of colliding if they arrive at that intersection at the same time. These scenarios are known well in advance and are carefully monitored by NASA's Jet Propulsion Laboratory in Pasadena, California, which sounded the alert regarding the possibility of a collision. With one week's advance notice, it looked like MAVEN and Phobos had a good chance of hitting each other on Monday, March 6, arriving at their orbit crossing point within about 7 seconds of each other. Given Phobos' size (modeled for simplicity as a 30-kilometer sphere, a bit larger than the actual moon in order to be conservative), they had a high probability of colliding if no action were taken. Said MAVEN Principal Investigator Bruce Jakosky of the University of Colorado in Boulder, "Kudos to the JPL navigation and tracking teams for watching out for possible collisions every day of the year, and to the MAVEN spacecraft team for carrying out the maneuver flawlessly." MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder. The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project and provided two science instruments for the mission. Lockheed Martin built the spacecraft and is responsible for mission operations. The University of California at Berkeley's Space Sciences Laboratory also provided four science instruments for the mission. NASA's Jet Propulsion Laboratory in Pasadena, California, provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations. News Media Contact By Nancy Neal Jones NASA's Goddard Space Flight Center in Greenbelt, Maryland 301-286-0039 nancy.n.jo...@nasa.gov Laurie Cantillo NASA Headquarters, Washington Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov 2017-057 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Journal - February 27, 2017
http://dawn.jpl.nasa.gov/mission/journal_02_27_17.html Dawn Journal Dr. Marc Rayman February 27, 2017 Dear Pedawntic Readers, A sophisticated spaceship in orbit around an alien world has been firing its advanced ion engine to execute complex and elegant orbital acrobatics. On assignment from Earth at dwarf planet Ceres, Dawn is performing like the ace flier that it is. The spacecraft's activities are part of an ambitious bonus goal the team has recently devised for the extended mission. Dawn will maneuver to a location exactly on the line connecting Ceres and the sun and take pictures and spectra there. Measuring the opposition surge we explained last month will help scientists gain insight into the microscopic nature of the famous bright material in Occator Crater. Flying to that special position and acquiring the pictures and spectra will consume most of the rest of the extended mission, which concludes on June 30. This month, we will look at the probe's intricate maneuvers. Next month, we will delve more into the opposition surge itself, and in April we will describe Dawn's detailed plans for photography and spectroscopy. In May we will discuss further maneuvers that could provide a backup opportunity for observing the opposition surge in June. [Image of Ernutet Crater] This image combines several photographs of Ernutet Crater taken through different color filters in Dawn's science camera. (Ernutet was an Egyptian goddess, often depicted with the head of a cobra, who provided food and protected grains by eating pests such as rodents.) The colors have been enhanced to bring out subtle differences in the chemical composition of the material covering the ground that would not be visible to your unaided eye (even assuming your unaided eye were in the vicinity of Ceres). Using data acquired by the spacecraft's infrared mapping spectrometer, scientists have determined that the red regions are rich in organic compounds. The organic molecules are based on chains of carbon atoms and represent a class of chemicals important in biochemistry. Such a finding, along with Dawn's earlier discoveries of ice and other chemicals that likely were formed through interactions with water, makes Ceres very interesting for studies of astrobiology. Nevertheless, future colonists on Ceres would be expected to have little need for protection from native pestilential threats. The 32-mile (52-kilometer) Ernutet Crater is on this map at 53°N, 46°E. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA First, however, it is worth recalling that this is not Dawn's primary responsibility, which is to continue to measure cosmic rays in order to improve scientists' ability to establish the atomic species down to about a yard (meter) underground. Sensing the space radiation requires the spacecraft to stay more than 4,500 miles (7,200 kilometers) above the dwarf planet that is its gravitational master. The gamma ray and neutron detector will be operated continuously as Dawn changes its orbit and then performs the new observations. The ongoing high-priority radiation measurements will not be affected by the new plans. The principal objective of the orbital maneuvers is to swivel Dawn's orbit around Ceres. Imagine looking down on Ceres' north pole, with the sun far to the left. (To help your imagination, you might refer to this figure from last month. As we will explain in May, Dawn's orbital plane is slowly rotating clockwise, according to plan, and it is now even closer to vertical than depicted in January. That does not affect the following discussion.) From your perspective, looking edge-on at Dawn's orbit, its elliptical path looks like a line, just as does a coin seen from the edge. In its current orbit (labeled 6 in that figure), Dawn moves from the bottom to the top over the north pole. When it is over the south pole, on the other side of the orbit, it flies from the top of the figure back to the bottom. The purpose of the current maneuvering is to make Dawn travel instead from the left to the right over the north pole (and from the right to the left over the south pole). This is equivalent to rotating the plane of the orbit around the axis that extends through Ceres' poles and up to Dawn's altitude. From the sun's perspective, Dawn starts by revolving counterclockwise and the orbit is face-on. We want to turn it so it is edge-on to the sun. That may not sound very difficult. After all, it amounts mostly to turning right at the north pole or left at the south pole. Spaceships in science fiction do that all the time (although sometimes they turn right at the south pole). However, it turns out to be extremely difficult in reality, not to mention lacking the cool sounds. When going over the south pole, from the top of the figure to the bottom, the spacecraft has momentum in that direction. To turn, it needs to cancel that out and then develop momentum to the left.
[meteorite-list] Martian Winds Carve Mountains, Move Dust, Raise Dust (MSL)
https://www.jpl.nasa.gov/news/news.php?feature=6758 Martian Winds Carve Mountains, Move Dust, Raise Dust Jet Propulsion Laboratory February 27, 2017 Fast Facts: * Wind is a dominant force shaping landscapes on Mars, despite the thin air. * A recent study supports the idea that a mountain that is oddly in the middle of a Martian crater was formed by wind subtracting other material after the crater had been filled to the brim with sediments. * Modern winds in the crater show effects such as dusty whirlwinds, shifting sand and active dunes. * NASA's Mars rover Curiosity has begun investigating linear-shaped dunes during the crater's windy summer season. On Mars, wind rules. Wind has been shaping the Red Planet's landscapes for billions of years and continues to do so today. Studies using both a NASA orbiter and a rover reveal its effects on scales grand to tiny on the strangely structured landscapes within Gale Crater. NASA's Curiosity Mars rover, on the lower slope of Mount Sharp -- a layered mountain inside the crater -- has begun a second campaign of investigating active sand dunes on the mountain's northwestern flank. The rover also has been observing whirlwinds carrying dust and checking how far the wind moves grains of sand in a single day's time. Gale Crater observations by NASA's Mars Reconnaissance Orbiter have confirmed long-term patterns and rates of wind erosion that help explain the oddity of having a layered mountain in the middle of an impact crater. "The orbiter perspective gives us the bigger picture -- on all sides of Mount Sharp and the regional context for Gale Crater. We combine that with the local detail and ground-truth we get from the rover," said Mackenzie Day of the University of Texas, Austin, lead author of a research report in the journal Icarus about wind's dominant role at Gale. The combined observations show that wind patterns in the crater today differ from when winds from the north removed the material that once filled the space between Mount Sharp and the crater rim. Now, Mount Sharp itself has become a major factor in determining local wind directions. Wind shaped the mountain; now the mountain shapes the wind. The Martian atmosphere is about a hundred times thinner than Earth's, so winds on Mars exert much less force than winds on Earth. Time is the factor that makes Martian winds so dominant in shaping the landscape. Most forces that shape Earth's landscapes -- water that erodes and moves sediments, tectonic activity that builds mountains and recycles the planet's crust, active volcanism -- haven't influenced Mars much for billions of years. Sand transported by wind, even if infrequent, can whittle away Martian landscapes over that much time. How to Make a Layered Mountain Gale Crater was born when the impact of an asteroid or comet more than 3.6 billion years ago excavated a basin nearly 100 miles (160 kilometers) wide. Sediments including rocks, sand and silt later filled the basin, some delivered by rivers that flowed in from higher ground surrounding Gale. Curiosity has found evidence of that wet era from more than 3 billion years ago. A turning point in Gale's history -- when net accumulation of sediments flipped to net removal by wind erosion -- may have coincided with a key turning point in the planet's climate as Mars became drier, Day noted. Scientists first proposed in 2000 that the mound at the center of Gale Crater is a remnant from wind eroding what had been a totally filled basin. The new work calculates that the vast volume of material removed -- about 15,000 cubic miles (64,000 cubic kilometers) -- is consistent with orbital observations of winds' effects in and around the crater, when multiplied by a billion or more years. Other new research, using Curiosity, focuses on modern wind activity in Gale. The rover this month is investigating a type of sand dune that differs in shape from dunes the mission investigated in late 2015 and early 2016. Crescent-shaped dunes were the feature of the earlier campaign -- the first ever up-close study of active sand dunes anywhere other than Earth. The mission's second dune campaign is at a group of ribbon-shaped linear dunes. "In these linear dunes, the sand is transported along the ribbon pathway, while the ribbon can oscillate back and forth, side to side," said Nathan Bridges, a Curiosity science team member at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. The season at Gale Crater is now summer, the windiest time of year. That's the other chief difference from the first dune campaign, conducted during less-windy Martian winter. "We're keeping Curiosity busy in an area with lots of sand at a season when there's plenty of wind blowing it around," said Curiosity Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory, Pasadena, California. "One aspect we want to learn more about is the wind's effect
[meteorite-list] Tiny Asteroid Whizzes by Earth (2017 EA)
http://neo.jpl.nasa.gov/news/news194.html Tiny Asteroid Whizzes by Earth (2017 EA) March 2, 2017 Paul Chodas Center for NEO Studies (CNEOS) A small near-Earth asteroid less than 3 meters (10 feet) across whizzed safely past Earth today at a distance so close that it passed well inside the ring of geosynchronous satellites. Designated 2017 EA, the asteroid made its closest approach to Earth at 6:04 a.m. PST (9:04 a.m. EST / 14:04 UTC) at an altitude of only 14,500 kilometers (9000 miles) above the eastern Pacific Ocean. At its closest point, this asteroid was 20 times closer than the Moon; it then quickly moved into the daytime sky and can no longer be observed by ground-based telescopes. [Graphic] Asteroid 2017 EA Close Approach to Earth on March 2, 2017 (D. Farnocchia, NASA/JPL) 2017 EA was originally detected only 6 hours before closest approach by astronomers at the NASA-funded Catalina Sky Survey, near Tucson, Arizona. It was observed by several other observatories before it passed into the Earth's shadow just before closest approach. [Animation] Asteroid 2017 EA Close Approach to Earth on March 2, 2017 (R. Baalke, NASA/JPL) Even though 2017 EA was tracked for only a single day, its orbit is now known quite accurately. Computations by CNEOS indicate that the asteroid will not approach our planet this close again for at least a hundred years. Asteroid 2017 EA Close Approach to Earth on March 2, 2017 (D. Farnocchia, NASA/JPL) __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Discovers Evidence for Organic Material on Ceres
http://www.jpl.nasa.gov/news/news.php?feature=6751 Dawn Discovers Evidence for Organic Material on Ceres Jet Propulsion Laboratory February 16, 2017 NASA's Dawn mission has found evidence for organic material on Ceres, a dwarf planet and the largest body in the main asteroid belt between Mars and Jupiter. Scientists using the spacecraft's visible and infrared mapping spectrometer (VIR) detected the material in and around a northern-hemisphere crater called Ernutet. Organic molecules are interesting to scientists because they are necessary, though not sufficient, components of life on Earth. The discovery adds to the growing list of bodies in the solar system where organics have been found. Organic compounds have been found in certain meteorites as well as inferred from telescopic observations of several asteroids. Ceres shares many commonalities with meteorites rich in water and organics -- in particular, a meteorite group called carbonaceous chondrites. This discovery further strengthens the connection between Ceres, these meteorites and their parent bodies. "This is the first clear detection of organic molecules from orbit on a main belt body," said Maria Cristina De Sanctis, lead author of the study, based at the National Institute of Astrophysics, Rome. The discovery is reported in the journal Science. Data presented in the Science paper support the idea that the organic materials are native to Ceres. The carbonates and clays previously identified on Ceres provide evidence for chemical activity in the presence of water and heat. This raises the possibility that the organics were similarly processed in a warm water-rich environment. Significance of organics The organics discovery adds to Ceres' attributes associated with ingredients and conditions for life in the distant past. Previous studies have found hydrated minerals, carbonates, water ice, and ammoniated clays that must have been altered by water. Salts and sodium carbonate, such as those found in the bright areas of Occator Crater, are also thought to have been carried to the surface by liquid. "This discovery adds to our understanding of the possible origins of water and organics on Earth," said Julie Castillo-Rogez, Dawn project scientist based at NASA's Jet Propulsion Laboratory in Pasadena, California. Where are the organics? The VIR instrument was able to detect and map the locations of this material because of its special signature in near-infrared light. The organic materials on Ceres are mainly located in an area covering approximately 400 square miles (about 1,000 square kilometers). The signature of organics is very clear on the floor of Ernutet Crater, on its southern rim and in an area just outside the crater to the southwest. Another large area with well-defined signatures is found across the northwest part of the crater rim and ejecta. There are other smaller organic-rich areas several miles (kilometers) west and east of the crater. Organics also were found in a very small area in Inamahari Crater, about 250 miles (400 kilometers) away from Ernutet. In enhanced visible color images from Dawn's framing camera, the organic material is associated with areas that appear redder with respect to the rest of Ceres. The distinct nature of these regions stands out even in low-resolution image data from the visible and infrared mapping spectrometer. "We're still working on understanding the geological context for these materials," said study co-author Carle Pieters, professor of geological sciences at Brown University, Providence, Rhode Island. Next steps for Dawn Having completed nearly two years of observations in orbit at Ceres, Dawn is now in a highly elliptical orbit at Ceres, going from an altitude of 4,670 miles (7,520 kilometers) up to almost 5,810 miles (9,350 kilometers). On Feb. 23, it will make its way to a new altitude of around 12,400 miles (20,000 kilometers), about the height of GPS satellites above Earth, and to a different orbital plane. This will put Dawn in a position to study Ceres in a new geometry. In late spring, Dawn will view Ceres with the sun directly behind the spacecraft, such that Ceres will appear brighter than before, and perhaps reveal more clues about its nature. The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: http://dawn.jpl.nasa.gov/mission More information about Dawn is available at the following
[meteorite-list] Lasers Could Give Space Research its 'Broadband' Moment
http://www.jpl.nasa.gov/news/news.php?feature=6746 Lasers Could Give Space Research its 'Broadband' Moment Jet Propulsion Laboratory February 14, 2017 Thought your Internet speeds were slow? Try being a space scientist for a day. The vast distances involved will throttle data rates to a trickle. You're lucky if a spacecraft can send more than a few megabits per second (Mbps). But we might be on the cusp of a change. Just as going from dial-up to broadband revolutionized the Internet and made high-resolution photos and streaming video a given, NASA may be ready to undergo a similar "broadband" moment in coming years. The key to that data revolution will be lasers. For almost 60 years, the standard way to "talk" to spacecraft has been with radio waves, which are ideal for long distances. But optical communications, in which data is beamed over laser light, can increase that rate by as much as 10 to 100 times. High data rates will allow researchers to gather science faster, study sudden events like dust storms or spacecraft landings, and even send video from the surface of other planets. The pinpoint precision of laser communications is also well suited to the goals of NASA mission planners, who are looking to send spacecraft farther out into the solar system. "Laser technology is ideal for boosting downlink communications from deep space," said Abi Biswas, the supervisor of the Optical Communications Systems group at NASA's Jet Propulsion Laboratory, Pasadena, California. "It will eventually allow for applications like giving each astronaut his or her own video feed, or sending back higher-resolution, data-rich images faster." Science at the speed of light Both radio and lasers travel at the speed of light, but lasers travel in a higher-frequency bandwidth. That allows them to carry more information than radio waves, which is crucial when you're collecting massive amounts of data and have narrow windows of time to send it back to Earth. A good example is NASA's Mars Reconnaissance Orbiter, which sends science data at a blazing maximum of 6 Mbps. Biswas estimated that if the orbiter used laser comms technology with a mass and power usage comparable to its current radio system, it could probably increase the maximum data rate to 250 Mbps. On Earth, data is sent over far shorter distances and through infrastructure that doesn't exist yet in space, so it travels even faster. Increasing data rates would allow scientists to spend more of their time on analysis than on spacecraft operations. "It's perfect when things are happening fast and you want a dense data set," said Dave Pieri, a JPL research scientist and volcanologist. Pieri has led past research on how laser comms could be used to study volcanic eruptions and wildfires in near real-time. "If you have a volcano exploding in front of you, you want to assess its activity level and propensity to keep erupting. The sooner you get and process that data, the better." That same technology could apply to erupting cryovolcanoes on icy moons around other planets. Pieri noted that compared to radio transmission of events like these, "laser comms would up the ante by an order of magnitude." Clouding the future of lasers That's not to say the technology is perfect for every scenario. Lasers are subject to more interference from clouds and other atmospheric conditions than radio waves; pointing and timing are also challenges. Lasers also require ground infrastructure that doesn't yet exist. NASA's Deep Space Network, a system of antenna arrays located across the globe, is based entirely on radio technology. Ground stations would have to be developed that could receive lasers in locations where skies are reliably clear. Radio technology won't be going away. It works in rain or shine, and will continue to be effective for low-data uses like providing commands to spacecraft. Next steps Two upcoming NASA missions will help engineers understand the technical challenges involved in conducting laser communications in space. What they'll learn will advance lasers toward becoming a common form of space communication in the future. The Laser Communications Relay Demonstration (LCRD), led by NASA's Goddard Space Flight Center in Greenbelt, Maryland, is due to launch in 2019. LCRD will demonstrate the relay of data using laser and radio frequency technology. It will beam laser signals almost 25,000 miles (40,000 kilometers) from a ground station in California to a satellite in geostationary orbit, then relay that signal to another ground station. JPL is developing one of the ground stations at Table Mountain in southern California. Testing laser communications in geostationary orbit, as LCRD will do, has practical applications for data transfer on Earth. Deep Space Optical Communications (DSOC), led by JPL, is scheduled to launch in 2023 as part of an upcoming NASA Discovery mission. That mission,
[meteorite-list] Scientists Shortlist Three Landing Sites for Mars 2020
http://www.jpl.nasa.gov/news/news.php?feature=6744 Scientists Shortlist Three Landing Sites for Mars 2020 Jet Propulsion Laboratory February 11, 2017 Participants in a landing site workshop for NASA's upcoming Mars 2020 mission have recommended three locations on the Red Planet for further evaluation. The three potential landing sites for NASA's next Mars rover include Northeast Syrtis (a very ancient portion of Mars' surface), Jezero crater, (once home to an ancient Martian lake), and Columbia Hills (potentially home to an ancient hot spring, explored by NASA's Spirit rover). More information on the landing sites can be found at: http://mars.nasa.gov/mars2020/mission/timeline/prelaunch/landing-site-selection/ Mars 2020 is targeted for launch in July 2020 aboard an Atlas V 541 rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. The rover will conduct geological assessments of its landing site on Mars, determine the habitability of the environment, search for signs of ancient Martian life, and assess natural resources and hazards for future human explorers. It will also prepare a collection of samples for possible return to Earth by a future mission. NASA's Jet Propulsion Laboratory will build and manage operations of the Mars 2020 rover for the NASA Science Mission Directorate at the agency's headquarters in Washington. For more information about NASA's Mars programs, visit: http://www.nasa.gov/mars News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, California 818-393-9011 a...@jpl.nasa.gov 2017-034 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Asteroid 2017 BQ6 Resembles Dungeons and Dragons Dice
http://www.jpl.nasa.gov/news/news.php?feature=6742 Asteroid Resembles Dungeons and Dragons Dice Jet Propulsion Laboratory February 10, 2017 [Images] This composite of 25 images of asteroid 2017 BQ6 was generated with radar data collected using NASA's Goldstone Solar System Radar in California's Mojave Desert. Image credit: NASA/JPL-Caltech/GSSR Radar images of asteroid 2017 BQ6 were obtained on Feb. 6 and 7 with NASA's 70-meter (230-foot) antenna at the Goldstone Deep Space Communications Complex in California. They reveal an irregular, angular-appearing asteroid about 660 feet (200 meters) in size that rotates about once every three hours. The images have resolutions as fine as 12 feet (3.75 meters) per pixel. "The radar images show relatively sharp corners, flat regions, concavities, and small bright spots that may be boulders," said Lance Benner of NASA's Jet Propulsion Laboratory in Pasadena, California, who leads the agency's asteroid radar research program. "Asteroid 2017 BQ6 reminds me of the dice used when playing Dungeons and Dragons. It is certainly more angular than most near-Earth asteroids imaged by radar." Asteroid 2017 BQ6 safely passed Earth on Feb. 6 at 10:36 p.m. PST (1:36 a.m. EST, Feb. 7) at about 6.6 times the distance between Earth and the moon (about 1.6 million miles, or 2.5 million kilometers). It was discovered on Jan. 26 by the NASA-funded Lincoln Near Earth Asteroid Research (LINEAR) Project, operated by MIT Lincoln Laboratory on the Air Force Space Command's Space Surveillance Telescope at White Sands Missile Range, New Mexico. Radar has been used to observe hundreds of asteroids. When these small, natural remnants of the formation of the solar system pass relatively close to Earth, deep space radar is a powerful technique for studying their sizes, shapes, rotation, surface features, and roughness, and for more precise determination of their orbital path. NASA's Jet Propulsion Laboratory, Pasadena, California, manages and operates NASA's Deep Space Network, including the Goldstone Solar System Radar, and hosts the Center for Near-Earth Object Studies for NASA's Near-Earth Object Observations Program within the agency's Science Mission Directorate. JPL hosts the Center for Near-Earth Object Studies for NASA's Near-Earth Object Observations Program within the agency's Science Mission Directorate. More information about asteroids and near-Earth objects can be found at: http://cneos.jpl.nasa.gov http://www.jpl.nasa.gov/asteroidwatch For more information about NASA's Planetary Defense Coordination Office, visit: http://www.nasa.gov/planetarydefense For asteroid and comet news and updates, follow AsteroidWatch on Twitter: twitter.com/AsteroidWatch News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, California 818-393-9011 a...@jpl.nasa.gov 2017-032 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA's Curiosity Rover Sharpens Paradox of Ancient Mars
http://www.jpl.nasa.gov/news/news.php?feature=6734 NASA's Curiosity Rover Sharpens Paradox of Ancient Mars Jet Propulsion Laboratory February 6, 2017 Fast Facts: * Curiosity rover findings add to a puzzle about ancient Mars because the same rocks that indicate a lake was present also indicate there was very little carbon dioxide in the air to help keep a lake unfrozen. * No carbonate has been found definitively in rock samples analyzed by Curiosity. * A new study calculates how much carbon dioxide could have been in the ancient atmosphere without resulting in carbonate detectable by the rover: not much. Mars scientists are wrestling with a problem. Ample evidence says ancient Mars was sometimes wet, with water flowing and pooling on the planet's surface. Yet, the ancient sun was about one-third less warm and climate modelers struggle to produce scenarios that get the surface of Mars warm enough for keeping water unfrozen. A leading theory is to have a thicker carbon-dioxide atmosphere forming a greenhouse-gas blanket, helping to warm the surface of ancient Mars. However, according to a new analysis of data from NASA's Mars rover Curiosity, Mars had far too little carbon dioxide about 3.5 billion years ago to provide enough greenhouse-effect warming to thaw water ice. The same Martian bedrock in which Curiosity found sediments from an ancient lake where microbes could have thrived is the source of the evidence adding to the quandary about how such a lake could have existed. Curiosity detected no carbonate minerals in the samples of the bedrock it analyzed. The new analysis concludes that the dearth of carbonates in that bedrock means Mars' atmosphere when the lake existed -- about 3.5 billion years ago -- could not have held much carbon dioxide. "We've been particularly struck with the absence of carbonate minerals in sedimentary rock the rover has examined," said Thomas Bristow of NASA's Ames Research Center, Moffett Field, California. "It would be really hard to get liquid water even if there were a hundred times more carbon dioxide in the atmosphere than what the mineral evidence in the rock tells us." Bristow is the principal investigator for the Chemistry and Mineralogy (CheMin) instrument on Curiosity and lead author of the study being published this week in the Proceedings of the National Academy of Sciences. Curiosity has made no definitive detection of carbonates in any lakebed rocks sampled since it landed in Gale Crater in 2012. CheMin can identify carbonate if it makes up just a few percent of the rock. The new analysis by Bristow and 13 co-authors calculates the maximum amount of carbon dioxide that could have been present, consistent with that dearth of carbonate. In water, carbon dioxide combines with positively charged ions such as magnesium and ferrous iron to form carbonate minerals. Other minerals in the same rocks indicate those ions were readily available. The other minerals, such as magnetite and clay minerals, also provide evidence that subsequent conditions never became so acidic that carbonates would have dissolved away, as they can in acidic groundwater. The dilemma has been building for years: Evidence about factors that affect surface temperatures -- mainly the energy received from the young sun and the blanketing provided by the planet's atmosphere -- adds up to a mismatch with widespread evidence for river networks and lakes on ancient Mars. Clues such as isotope ratios in today's Martian atmosphere indicate the planet once held a much denser atmosphere than it does now. Yet theoretical models of the ancient Martian climate struggle to produce conditions that would allow liquid water on the Martian surface for many millions of years. One successful model proposes a thick carbon-dioxide atmosphere that also contains molecular hydrogen. How such an atmosphere would be generated and sustained, however, is controversial. The new study pins the puzzle to a particular place and time, with an on-the-ground check for carbonates in exactly the same sediments that hold the record of a lake about a billion years after the planet formed. For the past two decades, researchers have used spectrometers on Mars orbiters to search for carbonate that could have resulted from an early era of more abundant carbon dioxide. They have found far less than anticipated. "It's been a mystery why there hasn't been much carbonate seen from orbit," Bristow said. "You could get out of the quandary by saying the carbonates may still be there, but we just can't see them from orbit because they're covered by dust, or buried, or we're not looking in the right place. The Curiosity results bring the paradox to a focus. This is the first time we've checked for carbonates on the ground in a rock we know formed from sediments deposited under water." The new analysis concludes that no more than a few tens of millibars of carbon dioxide could have
[meteorite-list] Dawn Journal - January 31, 2017
http://dawn.jpl.nasa.gov/mission/journal_01_31_17.html Dawn Journal Dr. Marc Rayman January 31, 2017 Dear Prodawns, Neudawns and Elecdawns, A deep-space robotic emissary from Earth is continuing to carry out its extraordinary mission at a distant dwarf planet. Orbiting high above Ceres, the sophisticated Dawn spacecraft is hard at work unveiling the secrets of the exotic alien world that has been its home for almost two years. Dawn's primary objective in this sixth orbital phase at Ceres (known as extended mission orbit 3, XMO3 or "this sixth orbital phase at Ceres") is to record cosmic rays. Doing so will allow scientists to remove that "noise" from the nuclear radiation measurements performed during the eight months Dawn operated in a low, tight orbit around Ceres. The result will be a cleaner signal, revealing even more about the atomic constituents down to about a yard (meter) underground. As we will see below, in addition to this ongoing investigation, soon the adventurer will begin pursuing a new objective in its exploration of Ceres. [Ikapati Crater Image] Dawn took this picture of Ikapati Crater on Jan. 24, 2016, from an altitude of 240 miles (385 kilometers), which is orbit 4 in the figure below. (Ikapati is an ancient Tagalog goddess whose name means "giver of food.") The 31-mile (50-kilometer) crater is geologically young, as evidenced by its clear, strong features. Note the difference in topography between the crater floor in the top half of the picture, with its many ridges, and in the bottom, which is smoother. The fractures run in different directions as well. Ikapati is at 34°N, 46°E on the map below. Full image and caption. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA With its uniquely capable ion propulsion system, Dawn has flown to orbits with widely varying characteristics. In contrast to the previous five observation orbits (and all the observation orbits at Vesta), XMO3 is elliptical. Over the course of almost eight days, the spacecraft sails from a height of about 4,670 miles (7,520 kilometers) up to almost 5,810 miles (9,350 kilometers) and back down. Dutifully following principles discovered by Johannes Kepler at the beginning of the 17th century and explained by Isaac Newton at the end of that century, Dawn's speed over this range of altitudes varies from 210 mph (330 kilometers per hour) when it is closest to Ceres to 170 mph (270 kilometers per hour) when it is farthest. Yesterday afternoon, the craft was at its highest for the current orbit. During the day today, the ship will descend from 5,790 miles (9,310 kilometers) to 5,550 miles (8,930 kilometers). As it does so, Ceres' gravity will gradually accelerate it from 170 mph (273 kilometers per hour) to 177 mph (285 kilometers per hour). (Usually we round the orbital velocity to the nearest multiple of 10. In this case, however, to show the change during one day, the values presented are more precise.) As we saw last month, the angle of XMO3 to the sun presents an opportunity to gain a new perspective on Ceres, with sunlight coming from a different angle. (We include the same figure here, because we will refer to it more below.) Last week, Dawn took advantage of that opportunity, seeing the alien landscapes in a new light as it took pictures for the first time since October. [Dawn XMO2 Image 10] This illustrates (and simplifies) the relative size and alignment of Dawn's six science orbits at Ceres. We are looking down on Ceres' north pole. The spacecraft follows polar orbits, and seen edge-on here, each orbit looks like a line. (Orbits 1, 2 and 6 extend off the figure to the lower right, on the night side. Like 3, 4 and 5, they are centered on Ceres.) The orbits are numbered chronologically. The first five orbits were circular. Orbit 6, which is XMO3, is elliptical, and the dotted section represents the range from the minimum to the maximum altitude. With the sun far to the left, the left side of Ceres is in daylight. Each time the spacecraft travels over the illuminated hemisphere in the different orbital planes, the landscape beneath it is lit from a different angle. Ceres rotates counterclockwise from this perspective (just as Earth does when viewed from the north). So higher numbers correspond to orbits that pass over ground closer to sunrise, earlier in the Cerean day. (Compare this diagram with this figure, which shows only the relative sizes of the first four orbits, with each one viewed face-on rather than edge-on.) Click on this image for a larger view. Image credit: NASA/JPL Dawn takes more than a week to revolve around Ceres, but Ceres turns on its axis in just nine hours. Because Dawn moves through only a small segment of its orbit in one Cerean day, it is almost as if the spacecraft hovers in place as the dwarf planet pirouettes beneath it. During one such period on Jan. 27, Dawn's high perch moved only from 11°N to 12°S latitude as Ceres
[meteorite-list] Mars Rover Curiosity Examines Possible Mud Cracks
http://www.jpl.nasa.gov/news/news.php?feature=6721 Mars Rover Curiosity Examines Possible Mud Cracks Jet Propulsion Laboratory January 17, 2017 Scientists used NASA's Curiosity Mars rover in recent weeks to examine slabs of rock cross-hatched with shallow ridges that likely originated as cracks in drying mud. "Mud cracks are the most likely scenario here," said Curiosity science team member Nathan Stein. He is a graduate student at Caltech in Pasadena, California, who led the investigation of a site called "Old Soaker," on lower Mount Sharp, Mars. If this interpretation holds up, these would be the first mud cracks -- technically called desiccation cracks -- confirmed by the Curiosity mission. They would be evidence that the ancient era when these sediments were deposited included some drying after wetter conditions. Curiosity has found evidence of ancient lakes in older, lower-lying rock layers and also in younger mudstone that is above Old Soaker. "Even from a distance, we could see a pattern of four- and five-sided polygons that don't look like fractures we've seen previously with Curiosity," Stein said. "It looks like what you'd see beside the road where muddy ground has dried and cracked." The cracked layer formed more than 3 billion years ago and was subsequently buried by other layers of sediment, all becoming stratified rock. Later, wind erosion stripped away the layers above Old Soaker. Material that had filled the cracks resisted erosion better than the mudstone around it, so the pattern from the cracking now appears as raised ridges. The team used Curiosity to examine the crack-filling material. Cracks that form at the surface, such as in drying mud, generally fill with windblown dust or sand. A different type of cracking with plentiful examples found by Curiosity occurs after sediments have hardened into rock. Pressure from accumulation of overlying sediments can cause underground fractures in the rock. These fractures generally have been filled by minerals delivered by groundwater circulating through the cracks, such as bright veins of calcium sulfate. Both types of crack-filling material were found at Old Soaker. This may indicate multiple generations of fracturing: mud cracks first, with sediment accumulating in them, then a later episode of underground fracturing and vein forming. "If these are indeed mud cracks, they fit well with the context of what we're seeing in the section of Mount Sharp Curiosity has been climbing for many months," said Curiosity Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory in Pasadena. "The ancient lakes varied in depth and extent over time, and sometimes disappeared. We're seeing more evidence of dry intervals between what had been mostly a record of long-lived lakes." Besides the cracks that are likely due to drying, other types of evidence observed in the area include sandstone layers interspersed with the mudstone layers, and the presence of a layering pattern called cross-bedding. This pattern can form where water was flowing more vigorously near the shore of a lake, or from windblown sediment during a dry episode. Scientists are continuing to analyze data acquired at the possible mud cracks and also watching for similar-looking sites. They want to check for clues not evident at Old Soaker, such as the cross-sectional shape of the cracks. The rover has departed that site, heading uphill toward a future rock-drilling location. Rover engineers at JPL are determining the best way to resume use of the rover's drill, which began experiencing intermittent problems last month with the mechanism that moves the drill up and down during drilling. Curiosity landed near Mount Sharp in 2012. It reached the base of the mountain in 2014 after successfully finding evidence on the surrounding plains that ancient Martian lakes offered conditions that would have been favorable for microbes if Mars has ever hosted life. Rock layers forming the base of Mount Sharp accumulated as sediment within ancient lakes billions of years ago. On Mount Sharp, Curiosity is investigating how and when the habitable ancient conditions known from the mission's earlier findings evolved into conditions drier and less favorable for life. For more information about Curiosity, visit: http://mars.jpl.nasa.gov/msl News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 / 818-393-9011 guy.webs...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov 2017-009 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Similar-Looking Ridges on Mars Have Diverse Origins
http://www.jpl.nasa.gov/news/news.php?feature=6725 Similar-Looking Ridges on Mars Have Diverse Origins Jet Propulsion Laboratory January 25, 2017 Fast Facts: * Many places on Mars have networks of ridges that intersect at angles to form polygons. * Martian polygonal-ridge features vary in size and origin. * A new project seeks volunteers to examine Mars images and identify sites with polygonal ridges Thin, blade-like walls, some as tall as a 16-story building, dominate a previously undocumented network of intersecting ridges on Mars, found in images from NASA's Mars Reconnaissance Orbiter. The simplest explanation for these impressive ridges is that lava flowed into pre-existing fractures in the ground and later resisted erosion better than material around them. A new survey of polygon-forming ridges on Mars examines this network in the Medusae Fossae region straddling the planet's equator and similar-looking networks in other regions of the Red Planet. "Finding these ridges in the Medusae Fossae region set me on a quest to find all the types of polygonal ridges on Mars," said Laura Kerber of NASA's Jet Propulsion Laboratory, Pasadena, California, lead author of the survey report published this month in the journal Icarus. The pattern is sometimes called boxwork ridges. Raised lines intersect as the outlines of multiple adjoining rectangles, pentagons, triangles or other polygons. Despite the similarity in shape, these networks differ in origin and vary in scale from inches to miles. Small and Large Examples Mars rover missions have found small versions they have been able to inspect up close. Some of these polygonal ridges, such as at "Garden City" seen by Curiosity, are veins deposited by mineral-laden groundwater moving through underground fissures, long before erosion exposed the veins. Curiosity recently also imaged small boxwork ridges that likely originated as mud cracks. At the other end of the size scale, ridges outline several rectangles each more than a mile (more than 2 kilometers) wide at a location called "Inca City" near Mars' south pole. These may have resulted from impact-related faults underground, with fractures filled by rising lava that hardened and was later exposed by erosion. "Polygonal ridges can be formed in several different ways, and some of them are really key to understanding the history of early Mars," Kerber said. "Many of these ridges are mineral veins, and mineral veins tell us that water was circulating underground." Polygonal ridges in the Nilosyrtis Mensae region of northern Mars may hold clues about ancient wet, possibly warm environments. Examples of them found so far tend to be in the same areas as water-related clues such as minerals that form in hot springs, clay-mineral layers and channels carved by ancient streams. A larger sample is needed to test this hypothesis. Volunteers Sought Kerber is seeking help from the public through a citizen-science project using images of Mars from the Context Camera (CTX) on Mars Reconnaissance Orbiter. "We're asking for volunteers to search for more polygonal ridges," she said. Finding as-yet-unidentified polygonal ridges in CTX images could improve understanding about their relationship to other features and also will help guide future observations with the High Resolution Imaging Science Experiment (HiRISE) camera to reveal details of the ridge networks. This citizen-science program, called Planet Four: Ridges, began Jan. 17 on a platform released by the Zooniverse, which hosts dozens of projects that enlist people worldwide to contribute to discoveries in fields ranging from astronomy to zoology. More information is at: http://ridges.planetfour.org Other Zooniverse Mars projects using data from CTX and HiRISE have drawn participation from more than 150,000 volunteers. On Earth, too, polygonal ridges have diverse origins. Examples include grand walls of lava that hardened underground then were exposed by erosion, and small ridge networks inside limestone caves, where erosion can be chemical as well as physical. With CTX, HiRISE and four other instruments, the Mars Reconnaissance Orbiter has been investigating Mars since 2006. Malin Space Science Systems, San Diego, built and operates CTX. The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp. of Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it. For additional information about the project, visit: http://mars.nasa.gov/mro News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 202-358-1077 /
[meteorite-list] A New Test for Life on Other Planets
http://www.jpl.nasa.gov/news/news.php?feature=6727 A New Test for Life on Other Planets Jet Propulsion Laboratory January 26, 2017 A simple chemistry method could vastly enhance how scientists search for signs of life on other planets. The test uses a liquid-based technique known as capillary electrophoresis to separate a mixture of organic molecules into its components. It was designed specifically to analyze for amino acids, the structural building blocks of all life on Earth. The method is 10,000 times more sensitive than current methods employed by spacecraft like NASA's Mars Curiosity rover, according to a new study published in Analytical Chemistry. The study was carried out by researchers from NASA's Jet Propulsion Laboratory, Pasadena, California. One of the key advantages of the authors' new way of using capillary electrophoresis is that the process is relatively simple and easy to automate for liquid samples expected on ocean world missions: it involves combining a liquid sample with a liquid reagent, followed by chemical analysis under conditions determined by the team. By shining a laser across the mixture -- a process known as laser-induced fluorescence detection -- specific molecules can be observed moving at different speeds. They get separated based on how quickly they respond to electric fields. While capillary electrophoresis has been around since the early 1980s, this is the first time it has been tailored specifically to detect extraterrestrial life on an ocean world, said lead author Jessica Creamer, a postdoctoral scholar at JPL. "Our method improves on previous attempts by increasing the number of amino acids that can be detected in a single run," Creamer said. "Additionally, it allows us to detect these amino acids at very low concentrations, even in highly salty samples, with a very simple 'mix and analyze' process." The researchers used the technique to analyze amino acids present in the salt-rich waters of Mono Lake in California. The lake's exceptionally high alkaline content makes it a challenging habitat for life, and an excellent stand-in for salty waters believed to be on Mars, or the ocean worlds of Saturn's moon Enceladus and Jupiter's moon Europa. The researchers were able to simultaneously analyze 17 different amino acids, which they are calling "the Signature 17 standard." These amino acids were chosen for study because they are the most commonly found on Earth or elsewhere. "Using our method, we are able to tell the difference between amino acids that come from non-living sources like meteorites versus amino acids that come from living organisms," said the project's principal investigator, Peter Willis of JPL. Key to detecting amino acids related to life is an aspect known as "chirality." Chiral molecules such as amino acids come in two forms that are mirror images of one another. Although amino acids from non-living sources contain approximately equal amounts of the "left" and "right"-handed forms, amino acids from living organisms on Earth are almost exclusively the "left-handed" form. It is expected that amino acid life elsewhere would also need to "choose" one of the two forms in order to create the structures of life. For this reason, chirality of amino acids is considered one of the most powerful signatures of life. "One of NASA's highest-level objectives is the search for life in the universe," Willis said. "Our best chance of finding life is by using powerful liquid-based analyses like this one on ocean worlds." Caltech in Pasadena, California, manages JPL for NASA. News Media Contact Andrew Good Jet Propulsion Laboratory, Pasadena, Calif. 818-393-2433 andrew.c.g...@jpl.nasa.gov 2017-017 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Selects Two Discovery Missions to Explore the Early Solar System
http://www.jpl.nasa.gov/news/news.php?feature=6713 NASA Selects Two Missions to Explore the Early Solar System Jet Propulsion Laboratory January 4, 2017 NASA has selected two missions that have the potential to open new windows on one of the earliest eras in the history of our solar system - a time less than 10 million years after the birth of our sun. The missions, known as Lucy and Psyche, were chosen from five finalists and will proceed to mission formulation, with the goal of launching in 2021 and 2023, respectively. "Lucy will visit a target-rich environment of Jupiter's mysterious Trojan asteroids, while Psyche will study a unique metal asteroid that's never been visited before," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate in Washington. "This is what Discovery Program missions are all about - boldly going to places we've never been to enable groundbreaking science." Lucy, a robotic spacecraft, is scheduled to launch in October 2021. It's slated to arrive at its first destination, a main belt asteroid, in 2025. >From 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter's gravity in two swarms that share the planet's orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter's current orbit. "This is a unique opportunity," said Harold F. Levison, principal investigator of the Lucy mission from the Southwest Research Institute in Boulder, Colorado. "Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system. Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins." Lucy will build on the success of NASA's New Horizons mission to Pluto and the Kuiper Belt, using newer versions of the RALPH and LORRI science instruments that helped enable the mission's achievements. Several members of the Lucy mission team also are veterans of the New Horizons mission. Lucy also will build on the success of the OSIRIS-REx mission to asteroid Bennu, with the OTES instrument and several members of the OSIRIS-REx team. The Psyche mission will explore one of the most intriguing targets in the main asteroid belt - a giant metal asteroid, known as 16 Psyche, about three times farther away from the sun than is the Earth. This asteroid measures about 130 miles (210 kilometers) in diameter and, unlike most other asteroids that are rocky or icy bodies, is thought to be comprised mostly of metallic iron and nickel, similar to Earth's core. Scientists wonder whether Psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to a number of violent collisions billions of years ago. The mission will help scientists understand how planets and other bodies separated into their layers - including cores, mantles and crusts - early in their histories. "This is an opportunity to explore a new type of world - not one of rock or ice, but of metal," said Psyche Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe. "16 Psyche is the only known object of its kind in the solar system, and this is the only way humans will ever visit a core. We learn about inner space by visiting outer space." Psyche, also a robotic mission, is targeted to launch in October of 2023, arriving at the asteroid in 2030, following an Earth gravity assist spacecraft maneuver in 2024 and a Mars flyby in 2025. In addition to selecting the Lucy and Psyche missions for formulation, the agency will extend funding for the Near Earth Object Camera (NEOCam) project for an additional year. The NEOCam space telescope is designed to survey regions of space closest to Earth's orbit, where potentially hazardous asteroids may be found. "JPL is delighted with the news that Psyche will be moving forward and for the additional support for the development of NEOCam. These two exciting and important missions will provide far greater understanding of the role asteroids play in our solar system," said JPL Director Mike Watkins. "These are true missions of discovery that integrate into NASA's larger strategy of investigating how the solar system formed and evolved," said NASA's Planetary Science Director Jim Green. "We've explored terrestrial planets, gas giants, and a range of other bodies orbiting the sun. Lucy will observe primitive remnants from farther out in the solar system, while Psyche will directly observe the interior of a planetary body. These additional pieces of the puzzle will help us understand how the sun and its family of planets formed, changed over time, and became places where life could develop and be sustained -
[meteorite-list] Dawn Journal - December 29, 2016
http://dawn.jpl.nasa.gov/mission/journal_12_29_16.html Dawn Journal Dr. Marc Rayman December 29, 2016 Dear Dawnimations, Dawn is concluding a remarkable year of exploring dwarf planet Ceres. At the beginning of 2016, the spacecraft was still a newcomer to its lowest altitude orbit (the fourth since arriving at Ceres in March 2015), and the flight team was looking forward to about three months of exciting work there to uncover more of the alien world'ss mysteries. [Animation] This animation shows many views of Occator Crater and its distinctive, captivating bright features. Dawn team members at the German Aerospace Center (DLR) combined photographs and other data collected by Dawn to make this video. (Unlike the visuals, the sounds are entirely speculative.) We have discussed the Occator findings shown here before. For details, see our last description, and follow the links from there to earlier Dawn Journals. Original video and caption. Video/image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA As it turned out, Dawn spent more than eight months conducting an exceptionally rewarding campaign of photography and other investigations, providing a richly detailed, comprehensive look at the extraterrestrial landscapes and garnering an extraordinary bounty of data. In September, the craft took advantage of its advanced ion propulsion system to fly to a new orbit from which it performed still more unique observations in October. Last month, the ship took flight again, and now it is concluding 2016 in its sixth science orbit. Dawn is in an elliptical orbit, sailing from about 4,670 miles (7,520 kilometers) up to up to almost 5,810 miles (9,350 kilometers) and back down. It takes nearly eight days to complete each orbital loop. Flying this high above Ceres allows Dawn to record cosmic rays to enhance the nuclear spectra it acquired at low altitude, improving the measurements of atomic constituents down to about a yard (meter) underground. [Animation] This animation shows Vesta (Dawn's first destination) and Ceres. Based on measurements of hydrogen, the colors encode the water content of the material within about a yard (meter) of the surface. We have seen before how the spacecraft's neutron spectrometer can make such a measurement. Here, as before, scientists have good reason to assume the hydrogen is in water molecules. Some of the water is in the form of ice and some is bound up in hydrated minerals. Even if it not exactly soggy, Ceres is much, much wetter than Vesta. In some regions on Vesta, there is no evidence of water at all (represented by red), and even the greatest concentration (the deepest blue) is only 0.04 percent. On Ceres, water is abundant, varying from 1.8 to 3.2 percent, or 45 to 80 times more prevalent than the highest concentration on Vesta. (The interior of Ceres harbors even more water than that.) Note that on Ceres, there is very little difference at different longitudes. The variability is much stronger with latitude: at greater distances from the equator, water is more plentiful. This fits with the temperatures being lower near the poles, allowing ice to be closer to the surface for very, very long times without sublimating away. (Below, we will discuss the presence of ice on the ground.) Vesta and Ceres are shown to scale in this animation. They are the two largest objects in the main asteroid belt. Vesta's equatorial diameter is 351 miles (565 kilometers). Ceres is 599 miles (963 kilometers) across at the equator. (Their rotation rates are not shown to scale. Vesta turns once in 5.3 hours, whereas Ceres takes 9.1 hours.) Video/image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA The spacecraft has been collecting cosmic ray data continuously since reaching this orbit (known to the Dawn team, imaginative readers of last month's Dawn Journal and now you as extended mission orbit 3, or XMO3). These measurements will continue until the end of the extended mission in June. But there is more in store for the indefatigable adventurer than monitoring space radiation. Based on studies of Dawn's extensive inspections of Ceres so far, scientists want to see certain sites at new angles and under different illumination conditions. Next month, Dawn will begin a new campaign of photography and visible spectroscopy. All of Dawn's five previous science orbits had different orientations from the sun. And now XMO3 will provide another unique perspective on the dwarf planet's terrain. The figure below shows what the orientation will be when the explorer turns its gaze once again on Ceres for the first set of new observations on Jan. 27, 2017. Dawn XMO2 Image 10 [Graphic} This illustrates (and simplifies) the relative size and alignment of Dawn's six science orbits at Ceres. We are looking down on Ceres' north pole. The spacecraft follows polar orbits, and seen edge-on here, each orbit looks like a line. (Orbits 1, 2 and 6 extend off the figure
[meteorite-list] NASA's NEOWISE Mission Spies One Comet, Maybe Two
http://www.jpl.nasa.gov/news/news.php?feature=6712 NASA's NEOWISE Mission Spies One Comet, Maybe Two Jet Propulsion Laboratory December 29, 2016 NASA's NEOWISE mission has recently discovered some celestial objects traveling through our neighborhood, including one on the blurry line between asteroid and comet. Another--definitely a comet--might be seen with binoculars through next week. An object called 2016 WF9 was detected by the NEOWISE project on Nov. 27, 2016. It's in an orbit that takes it on a scenic tour of our solar system. At its farthest distance from the sun, it approaches Jupiter's orbit. Over the course of 4.9 Earth-years, it travels inward, passing under the main asteroid belt and the orbit of Mars until it swings just inside Earth's own orbit. After that, it heads back toward the outer solar system. Objects in these types of orbits have multiple possible origins; it might once have been a comet, or it could have strayed from a population of dark objects in the main asteroid belt. 2016 WF9 will approach Earth's orbit on Feb. 25, 2017. At a distance of nearly 32 million miles (51 million kilometers) from Earth, this pass will not bring it particularly close. The trajectory of 2016 WF9 is well understood, and the object is not a threat to Earth for the foreseeable future. A different object, discovered by NEOWISE a month earlier, is more clearly a comet, releasing dust as it nears the sun. This comet, C/2016 U1 NEOWISE, "has a good chance of becoming visible through a good pair of binoculars, although we can't be sure because a comet's brightness is notoriously unpredictable," said Paul Chodas, manager of NASA's Center for Near-Earth Object (NEO) Studies at the Jet Propulsion Laboratory in Pasadena, California. As seen from the northern hemisphere during the first week of 2017, comet C/2016 U1 NEOWISE will be in the southeastern sky shortly before dawn. It is moving farther south each day and it will reach its closest point to the sun, inside the orbit of Mercury, on Jan. 14, before heading back out to the outer reaches of the solar system for an orbit lasting thousands of years. While it will be visible to skywatchers at Earth, it is not considered a threat to our planet either. NEOWISE is the asteroid-and-comet-hunting portion of the Wide-Field Infrared Survey Explorer (WISE) mission. After discovering more than 34,000 asteroids during its original mission, NEOWISE was brought out of hibernation in December of 2013 to find and learn more about asteroids and comets that could pose an impact hazard to Earth. If 2016 WF9 turns out to be a comet, it would be the 10th discovered since reactivation. If it turns out to be an asteroid, it would be the 100th discovered since reactivation. What NEOWISE scientists do know is that 2016 WF9 is relatively large: roughly 0.3 to 0.6 mile (0.5 to 1 kilometer) across. It is also rather dark, reflecting only a few percent of the light that falls on its surface. This body resembles a comet in its reflectivity and orbit, but appears to lack the characteristic dust and gas cloud that defines a comet. "2016 WF9 could have cometary origins," said Deputy Principal Investigator James "Gerbs" Bauer at JPL. "This object illustrates that the boundary between asteroids and comets is a blurry one; perhaps over time this object has lost the majority of the volatiles that linger on or just under its surface." Near-Earth objects (NEOs) absorb most of the light that falls on them and re-emit that energy at infrared wavelengths. This enables NEOWISE's infrared detectors to study both dark and light-colored NEOs with nearly equal clarity and sensitivity. "These are quite dark objects," said NEOWISE team member Joseph Masiero, "Think of new asphalt on streets; these objects would look like charcoal, or in some cases are even darker than that." NEOWISE data have been used to measure the size of each near-Earth object it observes. Thirty-one asteroids that NEOWISE has discovered pass within about 20 lunar distances from Earth's orbit, and 19 are more than 460 feet (140 meters) in size but reflect less than 10 percent of the sunlight that falls on them. The Wide-field Infrared Survey Explorer (WISE) has completed its seventh year in space after being launched on Dec. 14, 2009. Data from the NEOWISE mission are available on a website for the public and scientific community to use. A guide to the NEOWISE data release, data access instructions and supporting documentation are available at: http://wise2.ipac.caltech.edu/docs/release/neowise/ Access to the NEOWISE data products is available via the on-line and API services of the NASA/IPAC Infrared Science Archive. A list of peer-reviewed papers using the NEOWISE data is available at: http://neowise.ipac.caltech.edu/publications.html News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-354-5011 a...@jpl.nasa.gov Laurie Cantillo / Dwayne
[meteorite-list] Mars Odyssey Orbiter Recovering from Precautionary Pause in Activity
http://www.jpl.nasa.gov/news/news.php?feature=6711 Orbiter Recovering from Precautionary Pause in Activity Jet Propulsion Laboratory December 28, 2016 Mars Odyssey Mission Status Report NASA's Mars Odyssey orbiter, which has been in service at Mars since October 2001, put itself into safe mode -- a protective standby status -- on Dec. 26, while remaining in communication with Earth. The Odyssey project team has diagnosed the cause -- an uncertainty aboard the spacecraft about its orientation with regard to Earth and the sun -- and is restoring the orbiter to full operations. Odyssey's communication-relay service for assisting Mars rover missions is expected to resume this week, and Odyssey's own science investigations of the Red Planet are expected to resume next week. The orbiter's knowledge of its orientation was restored Dec. 26 by resetting the inertial measurement unit and the circuit card that serves as interface between that sensor, the flight software and the star tracker, for determining spacecraft attitude. The mission last experienced a similar fault and solution in December 2013. Mars Odyssey left Earth on April 7, 2001, entered orbit around Mars on Oct. 24, and began systematically examining Mars in February 2002. In December 2010, it surpassed the previous record for longevity of a robotic mission at Mars. The Mars Odyssey Project has been extending that record daily for more than six years. In addition to its direct contributions to planetary science, Odyssey provides important support for other missions in NASA's Journey to Mars through communication-relay service and observations of candidate landing sites. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Odyssey Project for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems, Denver, built the spacecraft and collaborates with JPL in mission operations. For more information about Odyssey, visit: http://mars.jpl.nasa.gov/odyssey News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Laurie Cantillo / Dwayne Brown NASA Headquarters, Washington 2202-358-1077 / 202-358-1726 laura.l.canti...@nasa.gov / dwayne.c.br...@nasa.gov __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] New Quasicrystal Found in Russian Meteorit
http://www.unifi.it/art-2306-discovery-of-yet-to-be-observed-extraterrestrial-quasicrystal.html
Discovery of yet to be observed extraterrestrial quasicrystal
University of Florence
December 16, 2016
As reported in a study by a scientist of the Department of Earth Sciences
appeared in Scientific Reports
A new quasicrystal coming from outer space surprised scientists with a
chemical composition never previously observed. ("Collisions in outer
space produced an icosahedral phase in the Khatyrka meteorite never observed
previously in the laboratory" in Scientific Reports). The study is the
output of an group of international researchers that includes Luca Bindi
of the University's Department of Earth Sciences.
The new extraterrestrial mineral, the third one presently identified,
was produced by collisions between space asteroids at the dawn of the
solar system. Its discovery proves that such materials could be a lot
more common than previously thought.
"Quasicrystals are unique minerals", reports Luca Bindi, associate professor
of Mineralogy, "and its atoms are set as if in a mosaic, in regular patterns,
but that do not repeat themselves periodically such as in ordinary crystals."
Up to now there were only two known natural quasicrystals (icosahedrite
and decagonite) also identified by the research group led by Biondi. The
first quasicrystal was identified in 2009 in a specimen of the Khatyrka
meteorite, found in Siberia and held by the Museum of Natural History
of the University of Florence.
Together with colleagues from Princeton University, the Smithsonian Institution
and the Russian Academy of Sciences, Bindi and his team have returned
to Siberia in 2011 where they collected further samples of the meteorite
in which the other two quasicrystals have been identified.
"Whereas the first two crystals reflect the chemical equivalent of synthetic
material discovered some years before thanks to the Nobel prize winner
Dan Shechtman who had synthesized them in the 1980s", continues Bindi,
"the quasicrystal material found now is something that has not been foreseen
by laboratory experiments and it shows how little we know of the formation
mechanisms of such materials that take shape and remain stable in exceptional
conditions and have innumerable technological applications".
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[meteorite-list] Mars Rover Opportunity Update: December 7-13, 2016
http://mars.nasa.gov/mer/mission/status.html#opportunity OPPORTUNITY UPDATE: Rover Performs Several Drives to Ancient Gully - sols 4576-4582, December 07, 2016-December 13, 2016: Opportunity is making progress towards the next science objective of the extended mission. The rover is headed toward an ancient water-carved gully about a kilometer south of the rover's current location on the rim of Endeavour Crater. The recent plans have emphasized driving. On Sol 4577 (Dec. 8, 2016), Opportunity intended a 59-feet (18-meter) drive to the southwest. However, the rover only achieved just over 39 feet (12 meters). The rover was using visual odometry (VO) to monitor her progress. After the 12-meters of progress VO failed to resolve surface features sufficiently to establish progress and stopped the drive. This is not uncommon when the local terrain around the rover may have few features or shadows of the rover confuse the algorithm. On Sol 4580 (Dec. 11, 2016), the rover made further progress to the southwest covering over 49 feet (15 meters). Because the rover is driving on slopes tilted away from the Sun, power has been constrained and drives limited in distance. Some sols following the drives have been 'recharge' sols, sols with limited rover activity. Another drive on Sol 4582 (Dec. 13, 2016), added another 56 feet (17 meters) again towards the southwest. And as always, extensive Navigation Camera (Navcam) and Panoramic Camera (Pancam) images have been collected following each drive. As of Sol 4582 (Dec. 13, 2016), the solar array energy production is 411 watt-hours with an atmospheric opacity (Tau) of 0.836 and a solar array dust factor of 0.675. Total odometry is 27.12 miles (43.65 kilometers). __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images: December 21, 2016
MARS RECONNAISSANCE ORBITER HIRISE IMAGES December 21, 2016 o Lace on Mars http://www.uahirise.org/ESP_046414_0990 Channels formed by sublimation of a layer of seasonal dry ice are so dense in this area that they look like lace. o Spiders on Mounds http://www.uahirise.org/ESP_046562_1005 This landform is uniquely Martian, formed in the spring as seasonal dry ice turns directly into gas. o Secondary Craters http://www.uahirise.org/ESP_046876_1465 Secondary impact craters are both interesting and vexing, but can be used to constrain the age of the surface where they fell. o Soffen Crater Floor http://www.uahirise.org/ESP_047561_1560 This crater on Mars was named after Dr. Gerald A. Soffen, project scientist for NASA's Viking program for Mars landers. http://hirise.lpl.arizona.edu/ Information about the Mars Reconnaissance Orbiter is online at http://www.nasa.gov/mro. The mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, for the NASA Science Mission Directorate, Washington, D.C. Lockheed Martin Space Systems, of Denver, is the prime contractor and built the spacecraft. HiRISE is operated by the University of Arizona. Ball Aerospace and Technologies Corp., of Boulder, Colo., built the HiRISE instrument. __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Where is the Ice on Ceres? New NASA Dawn Findings
http://www.jpl.nasa.gov/news/news.php?feature=6703 Where is the Ice on Ceres? New NASA Dawn Findings Jet Propulsion Laboratory December 15, 2061 At first glance, Ceres, the largest body in the main asteroid belt, may not look icy. Images from NASA's Dawn spacecraft have revealed a dark, heavily cratered world whose brightest area is made of highly reflective salts -- not ice. But newly published studies from Dawn scientists show two distinct lines of evidence for ice at or near the surface of the dwarf planet. Researchers are presenting these findings at the 2016 American Geophysical Union meeting in San Francisco. "These studies support the idea that ice separated from rock early in Ceres' history, forming an ice-rich crustal layer, and that ice has remained near the surface over the history of the solar system," said Carol Raymond, deputy principal investigator of the Dawn mission, based at NASA's Jet Propulsion Laboratory, Pasadena, California. Water ice on other planetary bodies is important because it is an essential ingredient for life as we know it. "By finding bodies that were water-rich in the distant past, we can discover clues as to where life may have existed in the early solar system," Raymond said. Ice is everywhere on Ceres Ceres' uppermost surface is rich in hydrogen, with higher concentrations at mid-to-high latitudes -- consistent with broad expanses of water ice, according to a new study in the journal Science. "On Ceres, ice is not just localized to a few craters. It's everywhere, and nearer to the surface with higher latitudes," said Thomas Prettyman, principal investigator of Dawn's gamma ray and neutron detector (GRaND), based at the Planetary Science Institute, Tucson, Arizona. Researchers used the GRaND instrument to determine the concentrations of hydrogen, iron and potassium in the uppermost yard (or meter) of Ceres. GRaND measures the number and energy of gamma rays and neutrons emanating from Ceres. Neutrons are produced as galactic cosmic rays interact with Ceres' surface. Some neutrons get absorbed into the surface, while others escape. Since hydrogen slows down neutrons, it is associated with fewer neutrons escaping. On Ceres, hydrogen is likely to be in the form of frozen water (which is made of two hydrogen atoms and one oxygen atom). Rather than a solid ice layer, there is likely to be a porous mixture of rocky materials in which ice fills the pores, researchers found. The GRaND data show that the mixture is about 10 percent ice by weight. "These results confirm predictions made nearly three decades ago that ice can survive for billions of years just beneath the surface of Ceres," Prettyman said. "The evidence strengthens the case for the presence of near-surface water ice on other main belt asteroids." Clues to Ceres' inner life Concentrations of iron, hydrogen, potassium and carbon provide further evidence that the top layer of material covering Ceres was altered by liquid water in Ceres' interior. Scientists theorize that the decay of radioactive elements within Ceres produced heat that drove this alteration process, separating Ceres into a rocky interior and icy outer shell. Separation of ice and rock would lead to differences in the chemical composition of Ceres' surface and interior. Because meteorites called carbonaceous chondrites were also altered by water, scientists are interested in comparing them to Ceres. These meteorites probably come from bodies that were smaller than Ceres, but had limited fluid flow, so they may provide clues to Ceres' interior history. The Science study shows that Ceres has more hydrogen and less iron than these meteorites, perhaps because denser particles sunk while brine-rich materials rose to the surface. Alternatively, Ceres or its components may have formed in a different region of the solar system than the meteorites. Ice in permanent shadow A second study, led by Thomas Platz of the Max Planck Institute for Solar System Research, Gottingen, Germany, and published in the journal Nature Astronomy, focused on craters that are persistently in shadow in Ceres' northern hemisphere. Scientists closely examined hundreds of cold, dark craters called "cold traps" -- at less than minus 260 degrees Fahrenheit (110 Kelvin), they are so chilly that very little of the ice turns into vapor in the course of a billion years. Researchers found deposits of bright material in 10 of these craters. In one crater that is partially sunlit, Dawn's infrared mapping spectrometer confirmed the presence of ice. [Images from NASA's Dawn spacecraft] This movie of images from NASA's Dawn spacecraft shows a crater on Ceres that is partly in shadow all the time. Such craters are called "cold traps." Dawn has shown that water ice could potentially be preserved in such place for very long amounts of time. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA This suggests that water ice can be stored in
[meteorite-list] Mars Rock-Ingredient Stew Seen as Plus for Habitability
http://www.jpl.nasa.gov/news/news.php?feature=6700 Mars Rock-Ingredient Stew Seen as Plus for Habitability Jet Propulsion Laboratory December 13, 2016 Fast Facts: * NASA's Curiosity Mars rover is finding patterns of change in rock composition at higher, younger layers of a mountain. * Ancient Mars sedimentary basins with groundwater were chemically active, a factor favorable for possible life. * Curiosity found boron on Mars, a first for this very soluble element. NASA's Curiosity rover is climbing a layered Martian mountain and finding evidence of how ancient lakes and wet underground environments changed, billions of years ago, creating more diverse chemical environments that affected their favorability for microbial life. Hematite, clay minerals and boron are among the ingredients found to be more abundant in layers farther uphill, compared with lower, older layers examined earlier in the mission. Scientists are discussing what these and other variations tell about conditions under which sediments were initially deposited, and about how groundwater moving later through the accumulated layers altered and transported ingredients. Effects of this groundwater movement are most evident in mineral veins. The veins formed where cracks in the layers were filled with chemicals that had been dissolved in groundwater. The water with its dissolved contents also interacted with the rock matrix surrounding the veins, altering the chemistry both in the rock and in the water. "There is so much variability in the composition at different elevations, we've hit a jackpot," said John Grotzinger, of Caltech in Pasadena, California. He and other members of Curiosity's science team presented an update about the mission Tuesday, Dec. 13, in San Francisco during the fall meeting of the American Geophysical Union. As the rover examines higher, younger layers, researchers are impressed by the complexity of the lake environments when clay-bearing sediments were being deposited, and also the complexity of the groundwater interactions after the sediments were buried. 'Chemical Reactor' "A sedimentary basin such as this is a chemical reactor," Grotzinger said. "Elements get rearranged. New minerals form and old ones dissolve. Electrons get redistributed. On Earth, these reactions support life." Whether Martian life has ever existed is still unknown. No compelling evidence for it has been found. When Curiosity landed in Mars' Gale Crater in 2012, the mission's main goal was to determine whether the area ever offered an environment favorable for microbes. The crater's main appeal for scientists is geological layering exposed in the lower portion of its central mound, Mount Sharp. These exposures offer access to rocks that hold a record of environmental conditions from many stages of early Martian history, each layer younger than the one beneath it. The mission succeeded in its first year, finding that an ancient Martian lake environment had all the key chemical ingredients needed for life, plus chemical energy available for life. Now, the rover is climbing lower on Mount Sharp to investigate how ancient environmental conditions changed over time. "We are well into the layers that were the main reason Gale Crater was chosen as the landing site," said Curiosity Deputy Project Scientist Joy Crisp of NASA's Jet Propulsion Laboratory, in Pasadena, California. "We are now using a strategy of drilling samples at regular intervals as the rover climbs Mount Sharp. Earlier we chose drilling targets based on each site's special characteristics. Now that we're driving continuously through the thick basal layer of the mountain, a series of drill holes will build a complete picture." Four recent drilling sites, from "Oudam" this past June through "Sebina" in October, are each spaced about 80 feet (about 25 meters) apart in elevation. This uphill pattern allows the science team to sample progressively younger layers that reveal Mount Sharp's ancient environmental history. Changing Environments One clue to changing ancient conditions is the mineral hematite. It has replaced less-oxidized magnetite as the dominant iron oxide in rocks Curiosity has drilled recently, compared with the site where Curiosity first found lakebed sediments. "Both samples are mudstone deposited at the bottom of a lake, but the hematite may suggest warmer conditions, or more interaction between the atmosphere and the sediments," said Thomas Bristow of NASA Ames Research Center, Moffett Field, California. He helps operate the Chemistry and Mineralogy (CheMin) laboratory instrument inside the rover, which identifies minerals in collected samples. Chemical reactivity occurs on a gradient of chemical ingredients' strength at donating or receiving electrons. Transfer of electrons due to this gradient can provide energy for life. An increase in hematite relative to magnetite indicates an environmental change
[meteorite-list] Dawn Journal - November 28, 2016
http://dawn.jpl.nasa.gov/mission/journal_11_28_16.html Dawn Journal Dr. Marc Rayman November 28, 2016 Dear Decadawnt Readers, Blue rope lights adorn Dawn mission control at JPL, but not because the flight team is in the holiday spirit (although they are in the holiday spirit). The felicitous display is more than decorative. The illumination indicates that the interplanetary spacecraft is thrusting with one of its ion engines, which emit a lovely, soft bluish glow in the forbidding depths of space. Dawn is completing another elegant spiral around dwarf planet Ceres, maneuvering to its sixth science orbit. Dawn's ion propulsion system has allowed the probe to accomplish a mission unlike any other, orbiting two distant extraterrestrial destinations. Even more than that, Dawn has taken advantage of the exceptional efficiency of its ion engines to fly to orbits at different altitudes and orientations while at Vesta and at Ceres, gaining the best perspectives for its photography and other scientific investigations. Occator on Ceres' Limb Dawn has thrust for a total of 5.7 years during its deep-space adventure. All that powered flight has imparted a change in the ship's velocity of 25,000 mph (40,000 kilometers per hour). As we have seen, this is not the spacecraft's actual speed, but it is a convenient measure of the effect of its propulsive work. Reaching Earth orbit requires only about 17,000 mph (less than 28,000 kilometers per hour). In fact, Dawn's gentle ion engines have delivered almost 98 percent of the change in speed that its powerful Delta 7925H-9.5 rocket provided. With nine external rocket engines and a core consisting of a first stage, a second stage and a third stage, the Delta boosted Dawn by 25,640 mph (41,260 kilometers per hour) from Cape Canaveral out of Earth orbit and onto its interplanetary trajectory, after which the remarkable ion engines took over. No other spacecraft has accomplished such a large velocity change under its own power. (The previous record holder, Deep Space 1, achieved 9,600 mph, or 15,000 kilometers per hour.) Early this year, we were highly confident Dawn would conclude its operational lifetime in its fourth orbit at Ceres (and remain there long after). But unexpectedly healthy and with an extension from NASA, Dawn is continuing its ambitious mission. After completing all of its tasks in its fifth scientific phase at Ceres, Dawn is pursuing new objectives by flying to another orbit for still more discoveries. Although we never anticipated adding a row to the table of Dawn's orbits, last presented in December 2015, we now have an updated version. [Table] As with the obscure Dawn code names for other orbits, this fifth orbit's name requires some explanation. The extended mission is devoted to undertaking activities not envisioned in the prime mission. That began with two extra months in the fourth mapping orbit performing many new observations, but because it was then the extended mission, that orbit was designated extended mission orbit 1, or XMO1. (It should have been EMO1, of course, but the team's spellchecker was offline on July 1, the day the extended mission started.) Therefore, the next orbit was XMO2. Dawn left XMO2 on Nov. 4, and we leave it to readers' imaginations to devise a name for the orbit the spacecraft is now maneuvering to. Surprisingly, Dawn is flying higher to enhance part of the scientific investigation that motivated going to the lowest orbit. We have explained before that Dawn's objective in powering its way down to the fourth mapping orbit was to make the most accurate measurements possible of gravity and of nuclear radiation emitted by the dwarf planet. For more than eight months, the explorer orbited closer to the alien world than the International Space Station is to Earth, and the gamma ray spectra and neutron spectra it acquired are outstanding, significantly exceeding all expectations. But ever-creative scientists have recognized that even with that tremendous wealth of data, Dawn can do still better. Let's look at this more carefully and consider an example to resolve the paradox of how going higher can yield an improvement. The gamma ray and neutron detector (GRaND) reveals some of Ceres' atomic constituents down to about a yard (meter) underground. The principal limitation in analyzing these spectra is "noise." In fact, noise limits the achievable accuracy of many scientific measurements. It isn't necessarily the kind of noise that you hear from loud machinery (nor from the mouth of your unhelpful parent, inattentive progeny or boring and verbose coworker), but all natural systems have something similar. Physical processes other than the ones of interest make unwanted contributions to the measurements. The part of a measurement scientists want is called the "signal." The part of a measurement scientists don't want is called the "noise." The quality of a
[meteorite-list] NASA Radio on Europe's New Mars Orbiter Aces Relay Test
http://www.jpl.nasa.gov/news/news.php?feature=6685 NASA Radio on Europe's New Mars Orbiter Aces Relay Test Jet Propulsion Laboratory November 29, 2016 Data from each of the two rovers active on Mars reached Earth last week in the successful first relay test of a NASA radio aboard Europe's new Trace Gas Orbiter (TGO). The transmissions from NASA rovers Opportunity and Curiosity, received by one of the twin Electra radios on the orbiter on Nov. 22, mark a strengthening of the international telecommunications network supporting Mars exploration. The orbiter's main radio for communications with Earth subsequently relayed onward to Earth the data received by Electra. The European Space Agency's (ESA's) ExoMars/Trace Gas Orbiter reached Mars on Oct. 19, 2016. As planned, its initial orbit shape is highly elliptical, ranging from as far as 60,000 miles (98,000 kilometers) above the surface to less than 200 miles (less than 310 kilometers). Each loop takes 4.2 days to complete. Frequent use of TGO's relay capability to support Mars rover operations is planned to begin more than a year from now. That's after the orbiter finishes adjusting its orbit to a near-circular path about 250 miles (400 kilometers) above Mars' surface. Meanwhile, four other active Mars orbiters also carry radios that can provide relay service for missions on the surface of Mars. The two active rovers routinely send data homeward via NASA orbiters Mars Odyssey and Mars Reconnaissance Orbiter (MRO). "The arrival of ESA's Trace Gas Orbiter at Mars, with its NASA-provided Electra relay payload on board, represents a significant step forward in our Mars relay capabilities," said Chad Edwards, manager of the Mars Relay Network Office within the Mars Exploration Program at NASA's Jet Propulsion Laboratory, Pasadena, California. "In concert with our three existing NASA orbiters and ESA's earlier Mars Express orbiter, we now have a truly international Mars relay network that will greatly increase the amount of data that future Mars landers and rovers can return from the surface of the Red Planet." NASA is on an ambitious journey to Mars that will include sending humans to the Red Planet. Current and future robotic spacecraft are leading the way and will prepare an infrastructure in advance for human missions. The JPL-designed Electra radios include special features for relaying data from a rover or stationary lander to an orbiter passing overhead. Relay of information from Mars-surface craft to Mars orbiters, then from the Mars orbiters to Earth, enables receiving much more data from the surface missions than would be possible with a direct-to-Earth radio link from the rovers or landers. "We already have almost 13 years' experience using ESA's Mars Express as an on-call backup for data relay from active Mars rovers, and TGO will greatly expand this to routine science-data relay," said Michel Denis, TGO flight director at ESA's European Space Operations Centre, Darmstadt, Germany. "In 2020, TGO will extend this relay support to ESA's ExoMars rover and the Russian Surface Platform, an important capability together with its science mission that enhances the international data network at Mars." As an example of Electra capabilities, during a relay session between an Electra on the surface and one on an orbiter, the radios can maximize data volume by actively adjusting the data rate to be slower when the orbiter is near the horizon from the surface robot's perspective, faster when it is overhead. Curiosity and Mars Reconnaissance Orbiter already use Electra technology to relay data. NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, in orbit since 2014, also carries an Electra radio. Due to improvements in the newest Electra radios and reduced interference levels, TGO's relay radios are expected to offer relay performance about double that of MRO's Electra. TGO's main X-band radio uses a dish antenna 87 inches (2.2 meters) in diameter to communicate with Earth-based antenna networks operated by ESA, NASA and Russia. JPL, a division of the California Institute of Technology in Pasadena, manages the Curiosity, Opportunity, MRO and Odyssey missions, and NASA's role in the ESA ExoMars program for the NASA Science Mission Directorate, Washington. For more about ESA's ExoMars program, including TGO, visit: http://exploration.esa.int/mars/ For more information about NASA's journey to Mars, visit: https://www.nasa.gov/topics/journeytomars News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.w.webs...@jpl.nasa.gov Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2016-305 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com
[meteorite-list] Curiosity Rover Team Examining New Drill Hiatus
http://www.jpl.nasa.gov/news/news.php?feature=6692 Curiosity Rover Team Examining New Drill Hiatus Jet Propulsion Laboratory December 5, 2016 NASA's Curiosity Mars rover is studying its surroundings and monitoring the environment, rather than driving or using its arm for science, while the rover team diagnoses an issue with a motor that moves the rover's drill. Curiosity is at a site on lower Mount Sharp selected for what would be the mission's seventh sample-collection drilling of 2016. The rover team learned Dec. 1 that Curiosity did not complete the commands for drilling. The rover detected a fault in an early step in which the "drill feed" mechanism did not extend the drill to touch the rock target with the bit. "We are in the process of defining a set of diagnostic tests to carefully assess the drill feed mechanism. We are using our test rover here on Earth to try out these tests before we run them on Mars," Curiosity Deputy Project Manager Steven Lee, at NASA's Jet Propulsion Laboratory in Pasadena, California, said Monday. "To be cautious, until we run the tests on Curiosity, we want to restrict any dynamic changes that could affect the diagnosis. That means not moving the arm and not driving, which could shake it." Two among the set of possible causes being assessed are that a brake on the drill feed mechanism did not disengage fully or that an electronic encoder for the mechanism's motor did not function as expected. Lee said that workarounds may exist for both of those scenarios, but the first step is to identify why the motor did not operate properly last week. The drill feed mechanism pushes the front of the drill outward from the turret of tools at the end of Curiosity's robotic arm. The drill collects powdered rock that is analyzed by laboratory instruments inside the rover. While arm movements and driving are on hold, the rover is using cameras and a spectrometer on its mast, and a suite of environmental monitoring capabilities. At the rover's current location, it has driven 9.33 miles (15.01 kilometers) since landing inside Mars' Gale Crater in August 2012. That includes more than half a mile (more than 840 meters) since departing a cluster of scenic mesas and buttes -- called "Murray Buttes" -- in September 2016. Curiosity has climbed 541 feet (165 meters) in elevation since landing, including 144 feet (44 meters) since departing Murray Buttes. The rover is climbing to sequentially higher and younger layers of lower Mount Sharp to investigate how the region's ancient climate changed, billions of years ago. Clues about environmental conditions are recorded in the rock layers. During its first year on Mars, the mission succeeded at its main goal by finding that the region once offered environmental conditions favorable for microbial life, if Mars has ever hosted life. The conditions in long-lived ancient freshwater Martian lake environments included all of the key chemical elements needed for life as we know it, plus a chemical source of energy that is used by many microbes on Earth. Curiosity's drill, as used at all 15 of the rock targets drilled so far, combines hammering action and rotating-bit action to penetrate the targets and collect sample material. The drilling attempt last week was planned as the mission's first using a non-percussion drilling method that relies only on the drill's rotary action. Short-circuiting in the percussion mechanism has occurred intermittently and unpredictably several times since first seen in February 2015. "We still have percussion available, but we would like to be cautious and use it for targets where we really need it, and otherwise use rotary-only where that can give us a sample," said Curiosity Project Scientist Ashwin Vasavada at JPL. JPL, a division of Caltech in Pasadena, California, manages NASA's Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington, and built the project's rover, Curiosity. For more information about the mission, visit: http://mars.jpl.nasa.gov/msl/ News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov 2016-309 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] New Ceres Views as Dawn Moves Higher
http://www.jpl.nasa.gov/news/news.php?feature=6678 New Ceres Views as Dawn Moves Higher Jet Propulsion Laboratory November 18, 2016 The brightest area on Ceres stands out amid shadowy, cratered terrain in a dramatic new view from NASA's Dawn spacecraft, taken as it looked off to the side of the dwarf planet. Dawn snapped this image on Oct. 16, from its fifth science orbit, in which the angle of the sun was different from that in previous orbits. Dawn was about 920 miles (1,480 kilometers) above Ceres when this image was taken -- an altitude the spacecraft had reached in early October. Occator Crater, with its central bright region and secondary, less-reflective areas, appears quite prominent near the limb, or edge, of Ceres. At 57 miles (92 kilometers) wide and 2.5 miles (4 kilometers) deep, Occator displays evidence of recent geologic activity. The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below, froze and then sublimated, meaning it turned from ice into vapor. The impact that formed the crater millions of years ago unearthed material that blanketed the area outside the crater, and may have triggered the upwelling of salty liquid. "This image captures the wonder of soaring above this fascinating, unique world that Dawn is the first to explore," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory, Pasadena, California. Dawn scientists also have released an image of Ceres that approximates how the dwarf planet's colors would appear to the human eye. This view, produced by the German Aerospace Center in Berlin, combines images taken from Dawn's first science orbit in 2015, using the framing camera's red, green and blue filters. The color was calculated based on the way Ceres reflects different wavelengths of light. The spacecraft has gathered tens of thousands of images and other information from Ceres since arriving in orbit on March 6, 2015. After spending more than eight months studying Ceres at an altitude of about 240 miles (385 kilometers), closer than the International Space Station is to Earth, Dawn headed for a higher vantage point in August. In October, while the spacecraft was at its 920-mile altitude, it returned images and other valuable insights about Ceres. On Nov. 4, Dawn began making its way to a sixth science orbit, which will be over 4,500 miles (7,200 kilometers) from Ceres. While Dawn needed to make several changes in its direction while spiraling between most previous orbits at Ceres, engineers have figured out a way for the spacecraft to arrive at this next orbit while the ion engine thrusts in the same direction that Dawn is already going. This uses less hydrazine and xenon fuel than Dawn's normal spiral maneuvers. Dawn should reach this next orbit in early December. One goal of Dawn's sixth science orbit is to refine previously collected measurements. The spacecraft's gamma ray and neutron spectrometer, which has been investigating the composition of Ceres' surface, will characterize the radiation from cosmic rays unrelated to Ceres. This will allow scientists to subtract "noise" from measurements of Ceres, making the information more precise. The spacecraft is healthy as it continues to operate in its extended mission phase, which began in July. During the primary mission, Dawn orbited and accomplished all of its original objectives at Ceres and protoplanet Vesta, which the spacecraft visited from July 2011 to September 2012. Dawn's mission is managed by NASA's Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: http://dawn.jpl.nasa.gov/mission More information about Dawn is available at the following sites: http://dawn.jpl.nasa.gov http://www.nasa.gov/dawn News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, CA 818-354-6425 elizabeth.lan...@jpl.nasa.gov 2016-297 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA, FEMA Hold Asteroid Emergency Planning Exercise
http://www.jpl.nasa.gov/news/news.php?feature=6669 NASA, FEMA Hold Asteroid Emergency Planning Exercise Jet Propulsion Laboratory November 4, 2016 What would we do if we discovered a large asteroid on course to impact Earth? While highly unlikely, that was the high-consequence scenario discussed by attendees at an Oct. 25 NASA-FEMA tabletop exercise in El Segundo, California. The third in a series of exercises hosted jointly by NASA and FEMA -- the Federal Emergency Management Agency -- the simulation was designed to strengthen the collaboration between the two agencies, which have Administration direction to lead the U.S. response. "It's not a matter of if -- but when -- we will deal with such a situation," said Thomas Zurbuchen, Associate Administrator for NASA's Science Mission Directorate in Washington. "But unlike any other time in our history, we now have the ability to respond to an impact threat through continued observations, predictions, response planning and mitigation." The exercise provided a forum for the planetary science community to show how it would collect, analyze and share data about a hypothetical asteroid predicted to impact Earth. Emergency managers discussed how that data would be used to consider some of the unique challenges an asteroid impact would present-for preparedness, response and public warning. "It is critical to exercise these kinds of low-probability but high-consequence disaster scenarios," FEMA Administrator Craig Fugate said. "By working through our emergency response plans now, we will be better prepared if and when we need to respond to such an event." Exercise attendees included representatives from NASA, FEMA, NASA's Jet Propulsion Laboratory, the Department of Energy's National Laboratories, the U.S. Air Force, and the California Governor's Office of Emergency Services. The exercise simulated a possible impact four years from now -- a fictitious asteroid imagined to have been discovered this fall with a 2 percent probability of impact with Earth on Sept. 20, 2020. The simulated asteroid was initially estimated to be between 300 and 800 feet (100 and 250 meters) in size, with a possibility of making impact anywhere along a long swath of Earth, including a narrow band of area that crossed the entire United States. In the fictitious scenario, observers continued to track the asteroid for three months using ground-based telescope observations, and the probability of impact climbed to 65 percent. Then the next observations had to wait until four months later, due to the asteroid's position relative to the sun. Once observations could resume in May of 2017, the impact probability jumped to 100 percent. By November of 2017, it was simulated that the predicted impact would occur somewhere in a narrow band across Southern California or just off the coast in the Pacific Ocean. While mounting a deflection mission to move the asteroid off its collision course had been simulated in previous tabletop exercises, this particular exercise was designed so that the time to impact was too short for a deflection mission to be feasible -- to pose a great future challenge to emergency managers faced with a mass evacuation of the metropolitan Los Angeles area. Scientists from JPL, Lawrence Livermore National Laboratory, Sandia National Laboratories, and The Aerospace Corporation presented predicted impact footprint models, population displacement estimates, information on infrastructure that would be affected, as well as other data that could realistically be known at various points throughout the exercise scenario. "The high degree of initial uncertainty coupled with the relatively long impact warning time made this scenario unique and especially challenging for emergency managers," said FEMA National Response Coordination Branch Chief Leviticus A. Lewis. "It's quite different from preparing for an event with a much shorter timeline, such as a hurricane." Attendees considered ways to provide accurate, timely and useful information to the public, while also addressing how to refute rumors and false information that could emerge in the years leading up to the hypothetical impact. "These exercises are invaluable for those of us in the asteroid science community responsible for engaging with FEMA on this natural hazard," said NASA Planetary Defense Officer Lindley Johnson. "We receive valuable feedback from emergency managers at these exercises about what information is critical for their decision making, and we take that into account when we exercise how we would provide information to FEMA about a predicted impact." NASA provides expert input to FEMA about the asteroid impact hazard through the Planetary Defense Coordination Office. NASA and FEMA will continue to conduct asteroid impact exercises and intend to expand participation in future exercises to include additional representatives from local and state
[meteorite-list] Curiosity Mars Rover Checks Odd-looking Iron Meteorite
http://www.jpl.nasa.gov/news/news.php?feature=6667 Curiosity Mars Rover Checks Odd-looking Iron Meteorite Jet Propulsion Laboratory November 2, 2016 [Image] The dark, golf-ball-size object in this composite, colorized view from the ChemCam instrument on NASA's Curiosity Mars rover is a nickel-iron meteorite, as confirmed by analysis using laser pulses from ChemCam on Oct. 30, 2016. The grid of bright spots on the rock resulted from the laser pulses. Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS/IAS/MSSS Laser-zapping of a globular, golf-ball-size object on Mars by NASA's Curiosity rover confirms that it is an iron-nickel meteorite fallen from the Red Planet's sky. Iron-nickel meteorites are a common class of space rocks found on Earth, and previous examples have been seen on Mars, but this one, called "Egg Rock," is the first on Mars examined with a laser-firing spectrometer. To do so, the rover team used Curiosity's Chemistry and Camera (ChemCam) instrument. Scientists of the Mars Science Laboratory (MSL) project, which operates the rover, first noticed the odd-looking rock in images taken by Curiosity's Mast Camera (Mastcam) at a site the rover reached by an Oct. 27 drive. "The dark, smooth and lustrous aspect of this target, and its sort of spherical shape attracted the attention of some MSL scientists when we received the Mastcam images at the new location," said ChemCam team member Pierre-Yves Meslin, at the Research Institute in Astrophysics and Planetology (IRAP), of France's National Center for Scientific Research (CNRS) and the University of Toulouse, France. ChemCam found iron, nickel and phosphorus, plus lesser ingredients, in concentrations still being determined through analysis of the spectrum of light produced from dozens of laser pulses at nine spots on the object. The enrichment in both nickel and phosphorus at some of the same points suggests the presence of an iron-nickel-phosphide mineral that is rare except in iron-nickel meteorites, Meslin said. Iron meteorites typically originate as core material of asteroids that melt, allowing the molten metal fraction of the asteroid's composition to sink to the center and form a core. "Iron meteorites provide records of many different asteroids that broke up, with fragments of their cores ending up on Earth and on Mars," said ChemCam team member Horton Newsom of the University of New Mexico, Albuquerque. "Mars may have sampled a different population of asteroids than Earth has." In addition, the study of iron meteorites found on Mars -- including examples found previously by Mars rovers -- can provide information about how long exposure to the Martian environment has affected them, in comparison with how Earth's environment affects iron meteorites. Egg Rock may have fallen to the surface of Mars many millions of years ago. Researchers will be analyzing the ChemCam data from the first few laser shots at each target point and data from subsequent shots at the same point, to compare surface versus interior chemistry. Egg Rock was found along the rover's path up a layer of lower Mount Sharp called the Murray formation, where sedimentary rocks hold records of ancient lakebed environments on Mars. The main science goal for Curiosity's second extended mission, which began last month, is to investigate how ancient environmental conditions changed over time. The mission has already determined that this region once offered conditons favorable for microbial life, if any life ever existed on Mars. Curiosity was launched five years ago this month, on Nov. 26, 2011, from Cape Canaveral Air Force Station, Florida. It landed inside Gale Crater, near the foot of Mount Sharp, in August 2012. The rover remains in good condition for continuing its investigations, after working more than twice as long as its originally planned prime mission of about 23 months, though two of its 10 science instruments have recently shown signs of potentially reduced capability. The neutron-generating component of Curiosity's Dynamic Albedo of Neutrons (DAN) instrument, designed for working through the prime mission, is returning data showing reduced voltage. Even if DAN could no longer generate neutrons, the instrument could continue to check for water molecules in the ground by using its passive mode. The performance of the wind-sensing capability from Curiosity's Rover Environmental Monitoring Station (REMS) is also changing, though that instrument still returns other Mars-weather data daily, such as temperatures, humidity and pressure. Analysis is in progress for fuller diagnosis of unusual data from DAN, which was provided by Russia, and REMS, provided by Spain. The U.S. Department of Energy's Los Alamos National Laboratory in Los Alamos, New Mexico, developed ChemCam in partnership with scientists and engineers funded by the French national space agency (CNES). Mastcam was built by Malin Space
[meteorite-list] Catalog of Known Near-Earth Asteroids Tops 15, 000
http://www.jpl.nasa.gov/news/news.php?feature=6664 Catalog of Known Near-Earth Asteroids Tops 15,000 Jet Propulsion Laboratory October 27, 2016 The number of discovered near-Earth asteroids (NEAs) now tops 15,000, with an average of 30 new discoveries added each week. This milestone marks a 50 percent increase in the number of known NEAs since 2013, when discoveries reached 10,000 in August of that year. Surveys funded by NASA's Near Earth Object (NEO) Observations Program (NEOs include both asteroids and comets) account for more than 95 percent of discoveries so far. The 15,000th near-Earth asteroid is designated 2016 TB57. It was discovered on Oct. 13 by observers at the Mount Lemmon Survey, an element of the NASA-funded Catalina Sky Survey in Tucson, Arizona. 2016 TB57 is a rather small asteroid -- about 50 to 115 feet (16 to 36 meters) in size -- that will come closest to Earth on Oct. 31 at just beyond five times the distance of the moon. It will safely pass Earth. A near-Earth asteroid is defined as one whose orbit periodically brings it within approximately 1.3 times Earth's average distance to the sun -- that is within 121 million miles (195 million kilometers) -- of the sun (Earth's average distance to the sun is about 93 million miles, or 150 million kilometers). This distance also then brings the asteroid within roughly 30 million miles (50 million kilometers) of Earth's orbit. Observers have already discovered more than 90 percent of the estimated population of the large NEOs -- those larger than 0.6 miles (one kilometer). "The rising rate of discovery is due to dedicated NEO surveys and upgraded telescopes coming online in recent years," said NASA's NEO Observations Program Manager Kelly Fast. "But while we're making great progress, we still have a long way to go." It is estimated by astronomers that only about 27 percent of the NEAs that are 460 feet (140 meters) and larger have been found to date. Congress directed NASA to find over 90 percent of objects this size and larger by the end of 2020. Currently, two NASA-funded NEO surveys -- the Catalina Sky Survey and the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) in Hawaii -- account for about 90 percent of new NEO discoveries. Both projects upgraded their telescopes in 2015, improving their discovery rates. A recent upgrade to one of the Catalina Sky Survey's telescopes resulted in a tripling of its average monthly NEO discovery rate. When the Pan-STARRS system increased the observing time it devoted to NEO searching to 90 percent, it increased its rate of discovery by a factor of three. Pan-STARRS also will add a second telescope to the hunt this fall. As more capable telescopes are deployed, the overall NEO survey effort will be able to find more objects as small as and smaller than 140 meters (460 feet). The NEO Observations Program is a primary element of NASA's Planetary Defense Coordination Office, which is responsible for finding, tracking and characterizing potentially hazardous NEOs, issuing warnings about possible impacts, and coordinating U.S. government planning for response to an actual impact threat. "While no known NEO currently poses a risk of impact with Earth over the next 100 years," says NASA Planetary Defense Officer Lindley Johnson, "we've found mostly the larger asteroids, and we have a lot more of the smaller but still potentially hazardous ones to find." For asteroid news and updates, follow AsteroidWatch on Twitter: http://www.twitter.com/AsteroidWatch News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 a...@jpl.nasa.gov Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2016-284 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Further Clues to Fate of Schiaparelli Mars Lander, Seen From Orbit
http://www.jpl.nasa.gov/news/news.php?feature=6663 Further Clues to Fate of Mars Lander, Seen From Orbit Jet Propulsion Laboratory October 27, 2016 The most powerful telescope orbiting Mars is providing new details of the scene near the Martian equator where Europe's Schiaparelli test lander hit the surface last week. An Oct. 25 observation using the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter shows three impact locations within about 0.9 mile (1.5 kilometers) of each other. An annotated view is available online at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21131 The scene shown by HiRISE includes three locations where hardware reached the ground. A dark, roughly circular feature is interpreted as where the lander itself struck. A pattern of rays extending from the circle suggests that a shallow crater was excavated by the impact, as expected given the premature engine shutdown. About 0.8 mile (1.4 kilometers) eastward, an object with several bright spots surrounded by darkened ground is likely the heat shield. About 0.6 mile (0.9 kilometer) south of the lander impact site, two features side-by-side are interpreted as the spacecraft's parachute and the back shell to which the parachute was attached. Additional images to be taken from different angles are planned and will aid interpretation of these early results. The test lander is part of the European Space Agency's ExoMars 2016 mission, which placed the Trace Gas Orbiter into orbit around Mars on Oct. 19. The orbiter will investigate the atmosphere and surface of Mars and provide relay communications capability for landers and rovers on Mars. Data transmitted by Schiaparelli during its descent through Mars' atmosphere is enabling analysis of why the lander's thrusters switched off prematurely. The new HiRISE imaging provides additional information, with more detail than visible in an earlier view with the Context Camera (CTX) on the Mars Reconnaissance Orbiter. With HiRISE, CTX and four other instruments, the Mars Reconnaissance Orbiter has been investigating Mars since 2006. The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp. of Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it. For additional information about the project, visit: http://mars.nasa.gov/mro News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Markus Bauer European Space Agency, Villanueva de la Cañada, Spain 0031 61 594 3 954 markus.ba...@esa.int Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2016-283 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] GRAIL Moon Mission Shares Insights into Giant Impacts
http://www.jpl.nasa.gov/news/news.php?feature=6662 NASA Moon Mission Shares Insights into Giant Impacts Jet Propulsion Laboratory October 27, 2016 Fast Facts: * Orientale basin is a giant, ringed impact crater on Earth's moon. * Until now, how impact craters with rings form had not been well understood. * Scientists have reconstructed Orientale's formation using data from NASA's GRAIL mission. New results from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission are providing insights into the huge impacts that dominated the early history of Earth's moon and other solid worlds, like Earth, Mars, and the satellites of the outer solar system. In two papers, published this week in the journal Science, researchers examine the origins of the moon's giant Orientale impact basin. The research helps clarify how the formation of Orientale, approximately 3.8 billion years ago, affected the moon's geology. Located along the moon's southwestern limb -- the left-hand edge as seen from Earth -- Orientale is the largest and best-preserved example of what's known as a "multi-ring basin." Impact craters larger than about 180 miles (300 kilometers) in diameter are referred to as basins. With increasing size, craters tend to have increasingly complex structures, often with multiple concentric, raised rings. Orientale is about 580 miles (930 kilometers) wide and has three distinct rings, which form a bullseye-like pattern. Multi-ring basins are observed on many of the rocky and icy worlds in our solar system, but until now scientists had not been able to agree on how their rings form. What they needed was more information about the crater's structure beneath the surface, which is precisely the sort of information contained in gravity science data collected during the GRAIL mission. The powerful impacts that created basins like Orientale played an important role in the early geologic history of our moon. They were extremely disruptive, world-altering events that caused substantial fracturing, melting and shaking of the young moon's crust. They also blasted out material that fell back to the surface, coating older features that were already there; scientists use this layering of ejected material to help determine the age of lunar features as they work to unravel the moon's complex history. The Importance of Orientale Because scientists realized that Orientale could be quite useful in understanding giant impacts, they gave special importance to observing its structure near the end of the GRAIL mission. The orbit of the mission's two probes was lowered so they passed less than 1.2 miles (2 kilometers) above the crater's mountainous rings. "No other planetary exploration mission has made gravity science observations this close to the moon. You could have waved to the twin spacecraft as they flew overhead if you stood at the ring's edge," said Sami Asmar, GRAIL project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. Of particular interest to researchers has been the size of the initial crater that formed during the Orientale impact. With smaller impacts, the initial crater is left behind, and many characteristics of the event can be inferred from the crater's size. Various past studies have suggested each of Orientale's three rings might be the remnant of the initial crater. In the first of the two new studies, scientists teased out the size of the transient crater from GRAIL's gravity field data. Their analysis shows that the initial crater was somewhere between the size of the basin's two innermost rings. "We've been able to show that none of the rings in Orientale basin represent the initial, transient crater," said GRAIL Principal Investigator Maria Zuber of the Massachusetts Institute of Technology in Cambridge, lead author of the first paper. "Instead, it appears that, in large impacts like the one that formed Orientale, the surface violently rebounds, obliterating signs of the initial impact." The analysis also shows that the impact excavated at least 816,000 cubic miles (3.4 million cubic kilometers) of material -- 153 times the combined volume of the Great Lakes. "Orientale has been an enigma since the first gravity observations of the moon, decades ago," said Greg Neumann, a co-author of the paper at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We are now able to resolve the individual crustal components of the bullseye gravity signature and correlate them with computer simulations of the formation of Orientale." Reproducing the Rings The second study describes how scientists successfully simulated the formation of Orientale to reproduce the crater's structure as observed by GRAIL. These simulations show, for the first time, how the rings of Orientale formed, which is likely similar for multi-ring basins in general. "Because our models show how the subsurface structure is formed, matching what
[meteorite-list] Water Detected on Largest Metallic Asteroid in Solar System (Psyche)
https://www.usgs.gov/news/water-detected-largest-metallic-asteroid-solar-system Water Detected on Largest Metallic Asteroid in Solar System USGS Release Date: October 20, 2016 Scientists have discovered possible evidence for water-rich minerals on the surface of the largest metallic asteroid in the solar system, according to a study by the U.S. Geological Survey and NASA. The asteroid, called Psyche, is 186 miles across and is made of almost pure nickel-iron metal. It is thought to be the remnant core of a planetary embryo that was mostly destroyed by impacts billions of years ago. Previous observations of Psyche had shown no evidence for water-rich minerals on its surface. However, new observations from the NASA Infrared Telescope Facility in Hawaii show evidence for water and/or hydroxyl on its surface. Results are published in The Astronomical Journal. While the source of these water molecules on Psyche remains a mystery, scientists propose a few possible mechanisms for their formation. It is possible that water-rich minerals detected on Psyche might have been delivered to its surface by carbonaceous asteroids that impacted Psyche in the distant past. "We think that Psyche may not be entirely exposed metallic core," says Driss Takir, lead author and scientist at the USGS Astrogeology Science Center in Flagstaff, Arizona. "What we see might instead have been a core-mantle boundary of a differentiated body that was disrupted via impacts. Solar radiation is another mechanism that can produce hydroxyl, which is a molecule consisting of one oxygen atom and one hydrogen atom, by interacting with the surface of Psyche." "This work underscores how much more we have to learn about asteroids," says Laszlo Kestay, Director of the USGS Astrogeology Science Center. "It will take more of this kind of careful work with telescopes on Earth, and spacecraft visiting asteroids, before we understand what treasures await us in space." Takir is a member of NASA's OSIRIS-REx mission and JAXA's Hayabusa 2 mission to collect carbonaceous samples from the water-rich asteroids, Bennu and Ryugu. "We are excited to continue studying Psyche, and other water-rich asteroids, to give us further insight into the distribution of potential resources in space," said Takir. This research on Psyche is funded by the USGS/NASA Eugene M. Shoemaker Fellowship, NASA Planetary Science Division Planetary Geology and Geophysics and Solar System Observations Programs. __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Computing Glitch May Have Doomed Schiaparelli Mars Lander
http://www.nature.com/news/computing-glitch-may-have-doomed-mars-lander-1.20861 Computing glitch may have doomed Mars lander Researchers sift through clues after Schiaparelli crash in hopes of averting mistakes in 2020 mission. Elizabeth Gibney Nature 25 October 2016 Photos of a huge circle of churned-up Martian soil leave few doubts: a European Space Agency (ESA) probe that was supposed to test landing technology on Mars crashed into the red planet instead, and may have exploded on impact. The events of 19 October may be painful for ESA scientists to recall, but they will now have to relive them over and over again in computer simulations. The lander, called Schiaparelli, was part of ESA's ExoMars mission, which is being conducted jointly with the Russian Space Agency Roscosmos. It was a prelude to a planned 2020 mission, when researchers aim to land a much larger scientific station and rover on Mars, which will drill up to 2-metres down to look for signs of ancient life in the planet's soil. Figuring out Schiaparelli's faults and rectifying them is a priority, says Jorge Vago, project scientist for ExoMars. "That's super important. I think it's on everybody's mind." Anatomy of a crash Unlike the British-led and ESA-operated Beagle 2 mission, which disappeared during its landing on Mars on Christmas Day 2003, Schiaparelli sent data to its mother ship during its descent. Preliminary analysis suggests that the lander began the manoeuvre flawlessly, braking against the planet's atmosphere and deploying its parachute. But at 4 minutes and 41 seconds into an almost 6-minute fall, something went wrong. The lander's heat shield and parachute ejected ahead of time, says Vago. Then thrusters, designed to decelerate the craft for 30 seconds until it was metres off the ground, engaged for only around 3 seconds before they were commanded to switch off, because the lander's computer thought it was on the ground. The lander even switched on its suite of instruments, ready to record Mars' weather and electrical field, although they did not collect data. "My guess is that at that point we were still too high. And the most likely scenario is that, from then, we just dropped to the surface," says Vago. The craft probably fell from a height of between 2 and 4 kilometres before slamming into the ground at more than 300 kilometres per hour, according to estimates based on images of the probe's likely crash site, taken by NASA's Mars Reconnaissance Orbiter on 20 October. The most likely culprit is a flaw in the craft's software or a problem in merging the data coming from different sensors, which may have led the craft to believe it was lower in altitude than it really was, says Andrea Accomazzo, ESA's head of solar and planetary missions. Accomazzo says that this is a hunch; he is reluctant to diagnose the fault before a full post-mortem has been carried out. But if he is right, that is both bad and good news. European-designed computing, software and sensors are among the elements of the lander that are to be reused on the ExoMars 2020 landing system, which, unlike Schiaparelli, will involve a mixture of European and Russian technology. But software glitches should be easier to fix than a fundamental problem with the landing hardware, which ESA scientists say seems to have passed its test with flying colours. "If we have a serious technological issue, then it's different, then we have to re-evaluate carefully. But I don't expect it to be the case," says Accomazzo. The ExoMars team will try to replicate the mistake using a virtual landing system designed to simulate the lander's hardware and software, says Vago, to make sure that scientists understand and can deal with the issue before redesigning any aspects of ExoMars 2020. 2020 vision The rover mission has already been delayed by two years, owing to hold-ups on both Russian and European sides, but Vago believes that making tweaks to its design will not push the mission back. "At this point, no one wants to think about flipping to 2022. It was painful enough to go from 2018 to 2020," he says. The 2020 mission still has a budget shortfall of around 300 million Euros (US$326 million), which ESA will request from European Union member states at a meeting of ministers in December. Asked at a press briefing on 20 October whether Schiaparelli's failure would jeopardize the mission, ESA director general Johann-Dietrich Worner said it wouldn't have any impact. "We have the function which we need for the 2020 mission, so we don't have to convince them, we just have to show them," he told reporters. But Vago is more pragmatic. "It would have been much nicer to be able to go to the ministers with a mission where both elements had performed flawlessly." ESA is keen to stress that overall, the ExoMars mission can be seen as a triumph: Schiaparelli sent back test data from the majority of its descent, and
[meteorite-list] Uranus May Have Two Undiscovered Moons
http://www.jpl.nasa.gov/news/news.php?feature=6657 Uranus May Have Two Undiscovered Moons Jet Propulsion Laboratory October 21, 2016 NASA's Voyager 2 spacecraft flew by Uranus 30 years ago, but researchers are still making discoveries from the data it gathered then. A new study led by University of Idaho researchers suggests there could be two tiny, previously undiscovered moonlets orbiting near two of the planet's rings. Rob Chancia, a University of Idaho doctoral student, spotted key patterns in the rings while examining decades-old images of Uranus' icy rings taken by Voyager 2 in 1986. He noticed the amount of ring material on the edge of the alpha ring -- one of the brightest of Uranus' multiple rings -- varied periodically. A similar, even more promising pattern occurred in the same part of the neighboring beta ring. "When you look at this pattern in different places around the ring, the wavelength is different -- that points to something changing as you go around the ring. There's something breaking the symmetry," said Matt Hedman, an assistant professor of physics at the University of Idaho, who worked with Chancia to investigate the finding. Their results will be published in The Astronomical Journal and have been posted to the pre-press site arXiv. Chancia and Hedman are well-versed in the physics of planetary rings: both study Saturn's rings using data from NASA's Cassini spacecraft, which is currently orbiting Saturn. Data from Cassini have yielded new ideas about how rings behave, and a grant from NASA allowed Chancia and Hedman to examine Uranus data gathered by Voyager 2 in a new light. Specifically, they analyzed radio occultations -- made when Voyager 2 sent radio waves through the rings to be detected back on Earth -- and stellar occultations, made when the spacecraft measured the light of background stars shining through the rings, which helps reveal how much material they contain. They found the pattern in Uranus' rings was similar to moon-related structures in Saturn's rings called moonlet wakes. The researchers estimate the hypothesized moonlets in Uranus' rings would be 2 to 9 miles (4 to 14 kilometers) in diameter -- as small as some identified moons of Saturn, but smaller than any of Uranus' known moons. Uranian moons are especially hard to spot because their surfaces are covered in dark material. "We haven't seen the moons yet, but the idea is the size of the moons needed to make these features is quite small, and they could have easily been missed," Hedman said. "The Voyager images weren't sensitive enough to easily see these moons." Hedman said their findings could help explain some characteristics of Uranus' rings, which are strangely narrow compared to Saturn's. The moonlets, if they exist, may be acting as "shepherd" moons, helping to keep the rings from spreading out. Two of Uranus' 27 known moons, Ophelia and Cordelia, act as shepherds to Uranus' epsilon ring. "The problem of keeping rings narrow has been around since the discovery of the Uranian ring system in 1977 and has been worked on by many dynamicists over the years," Chancia said. "I would be very pleased if these proposed moonlets turn out to be real and we can use them to approach a solution." Confirming whether or not the moonlets actually exist using telescope or spacecraft images will be left to other researchers, Chancia and Hedman said. They will continue examining patterns and structures in Uranus' rings, helping uncover more of the planet's many secrets. "It's exciting to see Voyager 2's historic Uranus exploration still contributing new knowledge about the planets," said Ed Stone, project scientist for Voyager, based at Caltech, Pasadena, California. Voyager 2 and its twin, Voyager 1, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn, and Voyager 2 also flew by Uranus and Neptune. Voyager 2 is the longest continuously operated spacecraft. It is expected to enter interstellar space in a few years, joining Voyager 1, which crossed over in 2012. Though far past the planets, the mission continues to send back unprecedented observations of the space environment in the solar system, providing crucial information on the environment our spacecraft travel through as we explore farther and farther from home. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, built the twin Voyager spacecraft and operates them for the Heliophysics Division within NASA's Science Mission Directorate in Washington. For more information about Voyager, visit: http://voyager.jpl.nasa.gov News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6425 elizabeth.lan...@jpl.nasa.gov Tara Roberts University of Idaho Communications 208-885-2097 trobe...@uidaho.edu Written by Tara Roberts 2016-276 __ Visit our Facebook page
[meteorite-list] Citizen Scientists Seek South Pole 'Spiders' on Mars
http://www.jpl.nasa.gov/news/news.php?feature=6654 Citizen Scientists Seek South Pole 'Spiders' on Mars Jet Propulsion Laboratory October 20, 2016 [Image] This image shows spidery channels eroded into Martian ground. This image shows spidery channels eroded into Martian ground. It is a Sept. 12, 2016, example from HiRISE camera high-resolution observations of more than 20 places that were chosen in 2016 on the basis of about 10,000 volunteers' examination of Context Camera lower-resolution views of larger areas. Image credit: NASA/JPL-Caltech/Univ. of Arizona Ten thousand volunteers viewing images of Martian south polar regions have helped identify targets for closer inspection, yielding new insights about seasonal slabs of frozen carbon dioxide and erosional features known as "spiders." >From the comfort of home, the volunteers have been exploring the surface of Mars by reviewing images from the Context Camera (CTX) on NASA's Mars Reconnaissance Orbiter and identifying certain types of seasonal terrains near Mars' south pole. These efforts by volunteers using the "Planet Four: Terrains" website have aided scientists who plan observations with the same orbiter's High Resolution Imaging Science Experiment (HiRISE) camera. HiRISE photographs much less ground but in much greater detail than CTX. Volunteers have helped identify more than 20 regions in mid-resolution images to investigate with higher resolution. "It's heartwarming to see so many citizens of planet Earth donate their time to help study Mars," said HiRISE Deputy Principal Investigator Candice Hansen, of the Planetary Science Institute, Tucson, Arizona. "Thanks to the discovery power of so many people, we're using HiRISE to take images of places we might not have studied without this assistance." Planetary scientist Meg Schwamb, of the Gemini Observatory, Hilo, Hawaii, presented results from the first year of this citizen science project Thursday at the annual meeting of the American Astronomical Society's Division for Planetary Sciences and the European Planetary Science Congress, in Pasadena, California. The type of terrain called spiders, or "araneiform" (from the Latin word for spiders), is characterized by multiple channels converging at a point, resembling a spider's long legs. Previous studies concluded that this ground texture results from extensive sheets of ice thawing bottom-side first as the ice is warmed by the ground below it. Thawed carbon dioxide gas builds up pressure, and the gas escapes through vents in the overlying sheet of remaining ice, pulling dust with it. This process carves the channels that resemble legs of a spider. "The trapped carbon dioxide gas that carves the spiders in the ground also breaks through the thawing ice sheet," Schwamb said. "It lofts dust and dirt that local winds then sculpt into hundreds of thousands of dark fans that are observed from orbit. For the past decade, HiRISE has been monitoring this process on other parts of the south pole. The 20 new regions have been added to this seasonal monitoring campaign. Without the efforts of the public, we wouldn't be able to see how these regions evolve over the spring and summer compared with other regions." Some of the HiRISE observations guided by the volunteers' input confirmed "spider" terrain in areas not previously associated with carbon dioxide slab ice. "From what we've learned about spider terrain elsewhere, slab ice must be involved at the locations of these new observations, even though we had no previous indication of it there," Hansen said. "Maybe it's related to the erodability of the terrain." Some of the new observations targeted with information from the volunteers confirm spiders in areas where the ground surface is made of material ejected from impact craters, blanketing an older surface. "Crater ejecta blankets are erodible. Perhaps on surfaces that are more erodable, relative to other surfaces, slab ice would not need to be present as long, or as thick, for spiders to form," Hansen said. "We have new findings, and new questions to answer, thanks to all the help from volunteers." The productive volunteer participation continues, and new CTX images have been added for examining additional areas in Mars' south polar region. Planet Four: Terrains is on a platform released by the Zooniverse, which hosts 48 projects that enlist people worldwide to contribute to discoveries in fields ranging from astronomy to zoology. For information about how to participate, visit: http://terrains.planetfour.org With CTX, HiRISE and four other instruments, the Mars Reconnaissance Orbiter has been investigating Mars since 2006. Malin Space Science Systems, San Diego, built and operates CTX. The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp. of Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena,
[meteorite-list] New Horizons: Possible Clouds on Pluto, Next Target is Reddish
http://www.jpl.nasa.gov/news/news.php?feature=6651 New Horizons: Possible Clouds on Pluto, Next Target is Reddish Jet Propulsion Laboratory October 18, 2016 [Image] Scientists from NASA's New Horizons mission have spotted signs of long run-out landslides on Pluto's largest moon, Charon. This perspective view of a chasm on Charon uses stereo reconstruction of images taken by two cameras on New Horizons, supplemented by a "shape-from-shading" algorithm. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Center The next target for NASA's New Horizons mission -- which made a historic flight past Pluto in July 2015 -- apparently bears a colorful resemblance to its famous, main destination. NASA's Hubble Space Telescope data suggests that 2014 MU69, a small Kuiper Belt object (KBO) about a billion miles (1.6 billion kilometers) beyond Pluto, is as red, if not redder, than Pluto. This is the first hint at the surface properties of the far-flung object that New Horizons will survey on Jan. 1, 2019. Mission scientists are discussing this and other Pluto and Kuiper Belt findings this week at the American Astronomical Society Division for Planetary Sciences (DPS) and European Planetary Science Congress (EPSC) meeting in Pasadena, California. "We're excited about the exploration ahead for New Horizons, and also about what we are still discovering from Pluto flyby data," said Alan Stern, principal investigator from Southwest Research Institute in Boulder, Colorado. "Now, with our spacecraft transmitting the last of its data from last summer's flight through the Pluto system, we know that the next great exploration of Pluto will require another mission to be sent there." Stern said that Pluto's complex, layered atmosphere is hazy and appears to be mostly free of clouds, but the team has spied a handful of potential clouds in images taken with New Horizons' cameras. "If there are clouds, it would mean the weather on Pluto is even more complex than we imagined," Stern said. Scientists already knew from telescope observations that Pluto's icy surface below that atmosphere varied widely in brightness. Data from the flyby not only confirms that, it also shows the brightest areas (such as sections of Pluto's large heart-shaped region) are among the most reflective in the solar system. "That brightness indicates surface activity," said Bonnie Buratti, a science team co-investigator from NASA's Jet Propulsion Laboratory in Pasadena. "Because we see a pattern of high surface reflectivity equating to activity, we can infer that the dwarf planet Eris, which is known to be highly reflective, is also likely to be active." While Pluto shows many kinds of activity, one surface process apparently missing is landslides. Surprisingly, though, they have been spotted on Pluto's largest moon, Charon, itself some 750 miles (1,200 kilometers) across. "We've seen similar landslides on other rocky and icy planets, such as Mars and Saturn's moon Iapetus, but these are the first landslides we've seen this far from the sun, in the Kuiper Belt," said Ross Beyer, a science team researcher from Sagan Center at the SETI Institute and NASA Ames Research Center, Moffett Field, California. "The big question is will they be detected elsewhere in the Kuiper Belt?" Both Hubble and cameras on the New Horizons spacecraft have been aimed at KBOs over the past two years, with New Horizons taking advantage of its unique vantage point in the Kuiper Belt to observe nearly a dozen small worlds in this barely explored region. MU69 is actually the smallest KBO to have its color measured -- and scientists have used that data to confirm the object is part of the so-called cold classical region of the Kuiper Belt, which is believed to contain some of the oldest, most prehistoric material in the solar system. "The reddish color tells us the type of Kuiper Belt object 2014 MU69 is," said Amanda Zangari, a New Horizons post-doctoral researcher from Southwest Research Institute. "The data confirms that on New Year's Day 2019, New Horizons will be looking at one of the ancient building blocks of the planets." The New Horizons spacecraft is currently 3.4 billion miles (5.5 billion kilometers) from Earth and about 340 million miles (540 million kilometers) beyond Pluto, speeding away from the sun at about nine miles (14 kilometers) every second. About 99 percent of the data New Horizons gathered and stored on its digital recorders during the Pluto encounter has now been transmitted back to Earth, with that transmission set to be completed Oct. 23. New Horizons has covered about one-third of the distance from Pluto to its next flyby target, which is now about 600 million miles (nearly 1 billion kilometers) ahead. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built and operates the New Horizons spacecraft, and manages the
[meteorite-list] Camera on MRO Shows Signs of Latest Mars Lander Schiaparelli
http://www.jpl.nasa.gov/news/news.php?feature=6658 Camera on Mars Orbiter Shows Signs of Latest Mars Lander Jet Propulsion Laboratory October 21, 2016 [Images] This comparison of before-and-after images. This comparison of before-and-after images shows two spots that likely appeared in connection with the Oct. 19, 2016, Mars arrival of the European Space Agency's Schiaparelli test lander. The images are from the Context Camera on NASA's Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/MSSS NASA's Mars Reconnaissance Orbiter has identified new markings on the surface of the Red Planet that are believed to be related to Europe's Schiaparelli test lander, which arrived at Mars on Oct. 19. The new image shows a bright spot that may be Schiaparelli's parachute, and a larger dark spot interpreted as resulting from the impact of the lander itself following a much longer free fall than planned, after thrusters switched off prematurely. It was taken by the Context Camera (CTX) on NASA's Mars Reconnaissance Orbiter and is available online, as a before-and-after comparison with an image from May 2016, at: http://mars.nasa.gov/multimedia/images/?ImageID=8131 The location information gained from acquiring the CTX image will be used for imaging the site with the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera. European Space Agency (ESA) and NASA researchers will analyze the images for information about the sequence of events on Schiaparelli's landing day, possibly supplementing data transmitted from the test module during its descent. The location of the bright spot interpreted as the parachute is 353.79 degrees east longitude, 2.07 degrees south latitude, closely matching ESA's calculation for the landing location based on landing-day data. This is within the planned landing area and about 3.3 miles (5.4 kilometers) west of the center of the landing target. A dark spot is larger and elliptical, approximately 50 by 130 feet (15 by 40 meters). It may be where the lander reached the surface and exposed darker ground. The test lander is part of ESA's ExoMars 2016 mission, which placed the Trace Gas Orbiter into orbit around Mars on Oct. 19. The orbiter will investigate Mars' atmosphere and provide relay communications capability for landers and rovers on the surface. With CTX, HiRISE and four other instruments, the Mars Reconnaissance Orbiter has been investigating Mars since 2006. Malin Space Science Systems, San Diego, built and operates CTX. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it. News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Markus Bauer European Space Agency, Villanueva de la Cañada, Spain 0031 61 594 3 954 markus.ba...@esa.int Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2016-278 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] ESA Celebrates ExoMars Orbiter Success, Keeps Vigil For Lost Lander
http://spaceflightnow.com/2016/10/19/esa-celebrates-exomars-orbiter-success-keeps-vigil-for-lost-lander/ ESA celebrates ExoMars orbiter success, keeps vigil for lost lander Stephen Clark SpaceFlight Now October 19, 2016 A European-built orbiter designed to seek out the source of methane on Mars slipped into orbit around the red planet Wednesday after a seven-month interplanetary journey, but mission control lost contact with an experimental landing probe just before touchdown. Both spacecraft - part of the joint European-Russian ExoMars program - reached Mars around the same time Wednesday for simultaneous maneuvers to swing into orbit and plunge into the red planet's atmosphere. The Schiaparelli lander, shaped like a flying saucer with a diameter of nearly 8 feet (2.4 meters), dived into the Martian atmosphere as expected around 1442 GMT (10:42 a.m. EDT) Wednesday. Designed for a technology demonstration mission, Schiaparelli had heat shield tiles, a parachute and nine rocket thrusters to slow its speed from 13,000 mph (21,000 kilometers per hour) to zero in less than six minutes. But something went wrong in the last phase of the descent, interrupting a real-time beacon signal sent back to Earth to a vast radio telescope array in Pune, India. The carrier tone went silent after mission controllers reported Schiaparelli's supersonic parachute had deployed, but the signal only told engineers whether the spacecraft was transmitting, and did not contain telemetry data that might reveal the root of the problem. European Space Agency officials waited to receive a recording of Schiaparelli's beacon signal from the Mars Express orbiter around the red planet to confirm some sort of glitch with the Indian antennas was not responsible for the loss of communications. "We saw the signal through the atmospheric phase - the descent phase. At a certain point, it stopped," said Paolo Ferri, head of ESA's mission operations department. "This was unexpected, but we couldn't conclude anything from that because this very weak signal picked up on the ground was coming from an experimental tool." The telescope array in India was never designed to communicate with deep space missions like Schiaparelli, but engineers added equipment to the antenna network - the largest in the world - for Wednesday's Mars landing in hopes of gaining real-time insight into the status of the mission. Otherwise, ground controllers would have had to wait for Mars Express for news on the 1,272-pound (577-kilogram) landing craft. It turns out the ground team at the European Space Operations Center in Darmstadt, Germany, had to wait all day Wednesday as data on Schiaparelli's landing trickled back to Earth and hopes for the mission's successful landing waned. The carrier signal from Schiaparelli relayed by Mars Express also abruptly ended shortly before landing, just as the beacon tone received in India. "The Mars Express measurement came - and confirmed exactly the same: the signal went through the majority of the descent phase, and it stopped at a certain point that we reckon was before the landing," Ferri said. "There could be many many reasons for that," Ferri said. "It's clear these are not good signs, but we will need more information." The newly-arrived Trace Gas Orbiter, Schiaparelli's mothership, recorded detailed telemetry broadcast by the lander - not just the beacon signal - and that data should be beamed back to Earth overnight, according to Ferri. "This is fundamental because we should remember that this landing was a test, and as part of the test, you want to know what happened," Ferri said. "If the landing were to fail, presumably from TGO we will know what was the last thing that worked all right," said Jorge Vago, ESA's ExoMars project scientist, in an interview with Spaceflight Now on Tuesday, before Schiaparelli's landing attempt. Officials hope to share more on what they know about Schiaparelli's fate in a press conference Thursday at 0800 GMT (4 a.m. EDT). Schiaparelli rode to Mars piggyback on the Trace Gas Orbiter after their tandem launch March 14 aboard a Russian Proton rocket, then separated Sunday for the final approach to the planet. Both ExoMars spacecraft were manufactured by an industrial team led by Thales Alenia Space. The orbiter fired its main engine at 1305 GMT (9:05 a.m. EDT), smoothly slowing the craft's velocity by more than 3,300 mph (1.5 kilometers per second) during a 139-minute burn. The final few minutes of the make-or-break rocket maneuver occurred as the spacecraft flew behind Mars, temporarily cutting off communications. When mission control regained contact with the Trace Gas Orbiter, telemetry showed the probe was healthy and had completed the orbit insertion burn as planned. The confirmation sparked a round of applause inside the ExoMars control center, but attention quickly turned back to Schiaparelli. "Part of the mission is a clear go," said Don McCoy, ESA's ExoMars
[meteorite-list] NASA's Kepler Gets the 'Big Picture' of Comet 67P
http://www.jpl.nasa.gov/news/news.php?feature=6641 NASA's Kepler Gets the 'Big Picture' of Comet 67P Jet Propulsion Laboratory October 7, 2016 On Sept. 30, the European Space Agency concluded its Rosetta mission and the study of comet 67P/Churyumov-Gerasimenko. During the final month of the mission, NASA's planet-hunting Kepler spacecraft had a unique opportunity to provide a "big picture" view of the comet as it was unobservable from Earth. Ground-based telescopes could not see comet 67P, because the comet's orbit placed it in the sky during daylight hours. >From Sept. 7 through Sept. 20, the Kepler spacecraft, operating in its K2 mission, fixed its gaze on comet 67P. From the distant vantage point of Kepler, the spacecraft could observe the comet's core and tail. The long-range global view of Kepler complements the close-in view of the Rosetta spacecraft, providing context for the high-resolution investigation Rosetta performed as it descended closer and closer to the comet. During the two-week period of study, Kepler took a picture of the comet every 30 minutes. The animation shows a period of 29.5 hours of observation from Sept. 17 through Sept. 18. The comet is seen passing through Kepler's field of view from top right to bottom left, as outlined by the diagonal strip. The white dots represent stars and other regions in space studied during K2's tenth observing campaign. As a comet travels through space, it sheds a tail of gas and dust. A comet's activity level can be obtained by measuring the reflected sunlight. Analyzing the Kepler data, scientists will be able to determine the amount of mass lost each day as comet 67P travels through the solar system. NASA Ames manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory, Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. For more information on Kepler and the K2 missions, go to: www.nasa.gov/kepler For more information on Rosetta, go to: https://www.nasa.gov/rosetta/ News Media Contact Elizabeth Landau Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6425 elizabeth.lan...@jpl.nasa.gov Michele Johnson Ames Research Center, Moffett Field, Calif. 650-604-6982 michele.john...@nasa.gov Written by Michele Johnson 2016-260 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA's Opportunity Rover to Explore Mars Gully
http://www.jpl.nasa.gov/news/news.php?feature=6642 NASA's Opportunity Rover to Explore Mars Gully Jet Propulsion Laboratory October 7, 2016 NASA's Opportunity Mars rover will drive down a gully carved long ago by a fluid that might have been water, according to the latest plans for the 12-year-old mission. No Mars rover has done that before. The longest-active rover on Mars also will, for the first time, visit the interior of the crater it has worked beside for the last five years. These activities are part of a two-year extended mission that began Oct. 1, the newest in a series of extensions going back to the end of Opportunity's prime mission in April 2004. Opportunity launched on July 7, 2003 and landed on Mars on Jan. 24, 2004 (PST), on a planned mission of 90 Martian days, which is equivalent to 92.4 Earth days. "We have now exceeded the prime-mission duration by a factor of 50," noted Opportunity Project Manager John Callas of NASA's Jet Propulsion Laboratory, Pasadena, California. "Milestones like this are reminders of the historic achievements made possible by the dedicated people entrusted to build and operate this national asset for exploring Mars." Opportunity begins its latest extended mission in the "Bitterroot Valley" portion of the western rim of Endeavour Crater, a basin 14 miles (22 kilometers) in diameter that was excavated by a meteor impact billions of years ago. Opportunity reached the edge of this crater in 2011 after more than seven years of investigating a series of smaller craters. In those craters, the rover found evidence of acidic ancient water that soaked underground layers and sometimes covered the surface. The gully chosen as the next major destination slices west-to-east through the rim about half a mile (less than a kilometer) south of the rover's current location. It is about as long as two football fields. "We are confident this is a fluid-carved gully, and that water was involved," said Opportunity Principal Investigator Steve Squyres of Cornell University, Ithaca, New York. "Fluid-carved gullies on Mars have been seen from orbit since the 1970s, but none had been examined up close on the surface before. One of the three main objectives of our new mission extension is to investigate this gully. We hope to learn whether the fluid was a debris flow, with lots of rubble lubricated by water, or a flow with mostly water and less other material." The team intends to drive Opportunity down the full length of the gully, onto the crater floor. The second goal of the extended mission is to compare rocks inside Endeavour Crater to the dominant type of rock Opportunity examined on the plains it explored before reaching Endeavour. "We may find that the sulfate-rich rocks we've seen outside the crater are not the same inside," Squyres said. "We believe these sulfate-rich rocks formed from a water-related process, and water flows downhill. The watery environment deep inside the crater may have been different from outside on the plain -- maybe different timing, maybe different chemistry." The rover team will face challenges keeping Opportunity active for another two years. Most mechanisms onboard still function well, but motors and other components have far exceeded their life expectancy. Opportunity's twin, Spirit, lost use of two of its six wheels before succumbing to the cold of its fourth Martian winter in 2010. Opportunity will face its eighth Martian winter in 2017. Use of Opportunity's non-volatile "flash" memory for holding data overnight was discontinued last year, so results of each day's observations and measurements must be transmitted that day or lost. In the two-year extended mission that ended last month, Opportunity explored the "Marathon Valley" area of Endeavour's western rim, documenting the geological context of water-related minerals that had been mapped there from orbital observations. Last month, the rover drove through "Lewis and Clark Gap," a low point in the wall separating Marathon Valley from Bitterroot Valley. A recent color panorama from the rover features "Wharton Ridge," which extends eastward from the gap. This week, Opportunity is investigating rock exposures next to "Spirit Mound," a prominent feature near the eastern end of Bitterroot Valley. The third main science goal of the new extended mission is to find and examine rocks from a geological layer that was in place before the impact that excavated Endeavour Crater. The science team has not yet determined whether the mound area will provide rocks that old. Opportunity and NASA's next-generation Mars rover, Curiosity, as well as three active NASA Mars orbiters, and surface missions to launch in 2018 and 2020 are steps in NASA's Journey to Mars, on track for sending humans there in the 2030s. JPL, a division of Caltech in Pasadena, California, built Opportunity and manages the mission for NASA's Science Mission Directorate,
[meteorite-list] Study Predicts Next Global Dust Storm on Mars
http://www.jpl.nasa.gov/news/news.php?feature=6638 Study Predicts Next Global Dust Storm on Mars Jet Propulsion Laboratory October 5, 2016 Global dust storms on Mars could soon become more predictable -- which would be a boon for future astronauts there -- if the next one follows a pattern suggested by those in the past. A published prediction, based on this pattern, points to Mars experiencing a global dust storm in the next few months. "Mars will reach the midpoint of its current dust storm season on October 29th of this year. Based on the historical pattern we found, we believe it is very likely that a global dust storm will begin within a few weeks or months of this date," James Shirley, a planetary scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. Local dust storms occur frequently on Mars. These localized storms occasionally grow or coalesce to form regional systems, particularly during the southern spring and summer, when Mars is closest to the sun. On rare occasions, regional storms produce a dust haze that encircles the planet and obscures surface features beneath. A few of these events may become truly global storms, such as one in 1971 that greeted the first spacecraft to orbit Mars, NASA's Mariner 9. Discerning a predictable pattern for which Martian years will have planet-encircling or global storms has been a challenge. The most recent Martian global dust storm occurred in 2007, significantly diminishing solar power available to two NASA Mars rovers then active halfway around the planet from each other -- Spirit and Opportunity. "The global dust storm in 2007 was the first major threat to the rovers since landing," said JPL's John Callas, project manager for Spirit and Opportunity. "We had to take special measures to enable their survival for several weeks with little sunlight to keep them powered. Each rover powered up only a few minutes each day, enough to warm them up, then shut down to the next day without even communicating with Earth. For many days during the worst of the storm, the rovers were completely on their own." Dust storms also will present challenges for astronauts on the Red Planet. Although the force of the wind on Mars is not as strong as portrayed in an early scene in the movie "The Martian," dust lofted during storms could affect electronics and health, as well as the availability of solar energy. The Red Planet has been observed shrouded by planet-encircling dust nine times since 1924, with the five most recent planetary storms detected in 1977, 1982, 1994, 2001 and 2007. The actual number of such events is no doubt higher. In some of the years when no orbiter was observing Mars up close, Mars was poorly positioned for Earth-based telescopic detection of dust storms during the Martian season when global storms are most likely. Shirley's 2015 paper in the journal Icarus reported finding a pattern in the occurrence of global dust storms when he factored in a variable linked to the orbital motion of Mars. Other planets have an effect on the momentum of Mars as it orbits the solar system's center of gravity. This effect on momentum varies with a cycle time of about 2.2 years, which is longer than the time it takes Mars to complete each orbit: about 1.9 years. The relationship between these two cycles changes constantly. Shirley found that global dust storms tend to occur when the momentum is increasing during the first part of the dust storm season. None of the global dust storms in the historic record occurred in years when the momentum was decreasing during the first part of the dust storm season. The paper noted that conditions in the current Mars dust-storm season are very similar to those for a number of years when global storms occurred in the past. Observations of the Martian atmosphere over the next few months will test whether the forecast is correct. Researchers at Malin Space Science Systems, in San Diego, post Mars weather reports each week based on observations using the Mars Color Imager camera on NASA's Mars Reconnaissance Orbiter. A series of local southern-hemisphere storms in late August grew into a major regional dust storm in early September, but subsided by mid-month without becoming global. Researchers will be closely watching to see what happens with the next regional storm. News Media Contact Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2016-256 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Flight Program Tests Mars Lander Vision System
http://www.jpl.nasa.gov/news/news.php?feature=6635 NASA Flight Program Tests Mars Lander Vision System Jet Propulsion Laboratory October 4, 2016 NASA tested new "eyes" for its next Mars rover mission on a rocket built by Masten Space Systems in Mojave, California, thanks in part to NASA's Flight Opportunities Program, or FOP. The agency's Jet Propulsion Laboratory in Pasadena, California, is leading development of the Mars 2020 rover and its Lander Vision System, or LVS. In 2014, the prototype vision system launched 1,066 feet (325 meters) into the air aboard Masten's rocket-powered "Xombie" test platform and helped guide the rocket to a precise landing at a predesignated target. LVS flew as part of a larger system of experimental landing technologies called the Autonomous Descent and Ascent Powered-flight Testbed, or ADAPT. LVS, a camera-based navigation system, photographs the terrain beneath a descending spacecraft and matches it with onboard maps allowing the craft to detect its location relative to landing hazards, such as boulders and outcroppings. The system can then direct the craft toward a safe landing at its primary target site or divert touchdown toward better terrain if there are hazards in the approaching target area. Image matching is aided by an inertial measurement unit that monitors orientation. The Flight Opportunities Program funded the Masten flight tests under the Space Technology Mission Directorate. The program obtains commercial suborbital space launch services to pursue science, technology and engineering to mature technology relevant to NASA's pursuit of space exploration. The program nurtures the emerging suborbital space industry and allows NASA to focus on deep space. Andrew Johnson, principal investigator in development of the Lander Vision System development, said the tests built confidence that the vision system will enable Mars 2020 to land safely. "By providing funding for flight tests, FOP motivated us to build guidance, navigation and control payloads for testing on Xombie," Johnson said. "In the end we showed a closed loop pinpoint landing demo that eliminated any technical concerns with flying the Lander Vision System on Mars 2020." According to "Lander Vision System for Safe and Precise Entry Descent and Landing," a 2012 abstract co-authored by Johnson for a Mars exploration workshop, LVS enables a broad range of potential landing sites for Mars missions. Typically, Mars landers have lacked the ability to analyze and react to hazards, the abstract says. To avoid hazards, mission planners selected wide-open landing sites with mostly flat terrain. As a result, landers and rovers were limited to areas with relatively limited geological features, and were unable to access many sites of high scientific interest with more complex and hazardous surface morphology. LVS will enable safe landing at these scientifically compelling Mars landing sites. An LVS-equipped mission allows for opportunities to land within more challenging environments and pursue new discoveries about Mars. With LVS baselined for inclusion on Mars 2020, the researchers are now focused on building the flight system ahead of its eventual role on the Red Planet. To learn more about NASA's flight opportunities program, visit: https://flightopportunities.nasa.gov/ To read more about NASA's Mars 2020 rover, visit: http://mars.nasa.gov/mars2020/ News Media Contact Leslie Williams NASA Armstrong Flight Research Center, Palmdale, Calif. 661-276-3893 leslie.a.willi...@nasa.gov Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Gina Anderson NASA Headquarters, Washington 202-358-1160 gina.n.ander...@nasa.gov 2016-253 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA's Curiosity Rover Begins Next Mars Chapter
http://www.jpl.nasa.gov/news/news.php?feature=6632 NASA's Curiosity Rover Begins Next Mars Chapter Jet Propulsion Laboratory October 3, 2016 After collecting drilled rock powder in arguably the most scenic landscape yet visited by a Mars rover, NASA's Curiosity mobile laboratory is driving toward uphill destinations as part of its two-year mission extension that commenced Oct. 1. The destinations include a ridge capped with material rich in the iron-oxide mineral hematite, about a mile-and-a-half (two-and-a-half kilometers) ahead, and an exposure of clay-rich bedrock beyond that. These are key exploration sites on lower Mount Sharp, which is a layered, Mount-Rainier-size mound where Curiosity is investigating evidence of ancient, water-rich environments that contrast with the harsh, dry conditions on the surface of Mars today. "We continue to reach higher and younger layers on Mount Sharp," said Curiosity Project Scientist Ashwin Vasavada, of NASA's Jet Propulsion Laboratory, Pasadena, California. "Even after four years of exploring near and on the mountain, it still has the potential to completely surprise us." Hundreds of photos Curiosity took in recent weeks amid a cluster of mesas and buttes of diverse shapes are fresh highlights among the more than 180,000 images the rover has taken since landing on Mars in August 2012. Newly available vistas include the rover's latest self-portrait from the color camera at the end of its arm and a scenic panorama from the color camera at the top of the mast. "Bidding good-bye to 'Murray Buttes,' Curiosity's assignment is the ongoing study of ancient habitability and the potential for life," said Curiosity Program Scientist Michael Meyer at NASA Headquarters, Washington. "This mission, as it explores the succession of rock layers, is reading the 'pages' of Martian history -- changing our understanding of Mars and how the planet has evolved. Curiosity has been and will be a cornerstone in our plans for future missions." The component images of the self-portrait were taken near the base of one of the Murray Buttes, at the same site where the rover used its drill on Sept. 18 to acquire a sample of rock powder. An attempt to drill at this site four days earlier had halted prematurely due to a short-circuit issue that Curiosity had experienced previously, but the second attempt successfully reached full depth and collected sample material. After departing the buttes area, Curiosity delivered some of the rock sample to its internal laboratory for analysis. This latest drill site -- the 14th for Curiosity -- is in a geological layer about 600 feet (180 meters) thick, called the Murray formation. Curiosity has climbed nearly half of this formation's thickness so far and found it consists primarily of mudstone, formed from mud that accumulated at the bottom of ancient lakes. The findings indicate that the lake environment was enduring, not fleeting. For roughly the first half of the new two-year mission extension, the rover team anticipates investigating the upper half of the Murray formation. "We will see whether that record of lakes continues further," Vasavada said. "The more vertical thickness we see, the longer the lakes were present, and the longer habitable conditions existed here. Did the ancient environment change over time? Will the type of evidence we've found so far transition to something else?" The "Hematite Unit" and "Clay Unit" above the Murray formation were identified from Mars orbiter observations before Curiosity's landing. Information about their composition, from the Compact Reconnaissance Imaging Spectrometer aboard NASA's Mars Reconnaissance Orbiter, made them high priorities as destinations for the rover mission. Both hematite and clay typically form in wet environments. Vasavada said, "The Hematite and the Clay units likely indicate different environments from the conditions recorded in older rock beneath them and different from each other. It will be interesting to see whether either or both were habitable environments." NASA approved Curiosity's second extended mission this summer on the basis of plans presented by the rover team. Additional extensions for exploring farther up Mount Sharp may be considered in the future. The Curiosity mission has already achieved its main goal of determining whether the landing region ever offered environmental conditions that would have been favorable for microbial life, if Mars has ever hosted life. The mission found evidence of ancient rivers and lakes, with a chemical energy source and all of the chemical ingredients necessary for life as we know it. The mission is also monitoring the modern environment of Mars, including natural radiation levels. Along with other robotic missions to the Red Planet, it is an important piece of NASA's Journey to Mars, leading toward human crew missions in the 2030s. JPL, a division of Caltech in Pasadena,
[meteorite-list] Extraterrestrial Impact Preceded Ancient Global Warming Event
http://news.rpi.edu/content/2016/10/13/extraterrestrial-impact-preceded-ancient-global-warming-event Extraterrestrial Impact Preceded Ancient Global Warming Event By Mary L. Martially Rensselaer Polytechnic Institute October 13, 2016 A comet strike may have triggered the Paleocene-Eocene Thermal Maximum (PETM), a rapid warming of the Earth caused by an accumulation of atmospheric carbon dioxide 56 million years ago, which offers analogs to global warming today. Sorting through samples of sediment from the time period, researchers at Rensselaer Polytechnic Institute discovered evidence of the strike in the form of microtektites - tiny dark glassy spheres typically formed by extraterrestrial impacts. The research will be published tomorrow in the journal Science. "This tells us that there was an extraterrestrial impact at the time this sediment was deposited - a space rock hit the planet," said Morgan Schaller, an assistant professor of earth and environmental sciences at Rensselaer, and corresponding author of the paper. "The coincidence of an impact with a major climate change is nothing short of remarkable." Schaller is joined in the research by Rensselaer professor Miriam Katz and graduate student Megan Fung, James Wright of Rutgers University, and Dennis Kent of Columbia University. Schaller was searching for fossilized remains of Foraminifera, a tiny organism that produces a shell, when he first noticed a microtektite in the sediment he was examining. Although it is common for researchers to search for fossilized remains in PETM sediments, microtektites have not been previously detected. Schaller and his team theorize this is because microtektites are typically dark in color, and do not stand out on the black sorting tray researchers use to search for light-colored fossilized remains. Once Schaller noticed the first microtektite, the researchers switched to a white sorting tray, and began to find more. At peak abundance, the research team found as many as three microtektites per gram of sediment examined. Microtektites are typically spherical, or tear-drop shaped, and are formed by an impact powerful enough to melt and vaporize the target area, casting molten ejecta into the atmosphere. Some microtektites from the samples contained "shocked quartz," definitive evidence of their impact origin, and exhibited microcraters or were sintered together, evidence of the speed at which they were traveling as they solidified and hit the ground. Atmospheric carbon dioxide increased rapidly during the PETM, and an accompanying spike in global temperatures of about 5 to 8 degrees Celsius lasted for about 150,000 years. Although this much is known, the source of the carbon dioxide had not been determined, and little is known about the exact sequence of events - such as how rapidly carbon dioxide entered the atmosphere, how quickly and at what rate temperatures began to rise, and how long it took to reach a global high temperature. One clue can be found in a sudden shift in the ratio of carbon isotopes (atoms containing a number of neutrons unequal to the protons in their nucleus) in certain fossils from the time period. In particular, Foraminifera, or "forams," produce a shell whose chemistry is representative of atmospheric and ocean carbon isotopes. The research team initially set out to examine the ratio of carbon isotopes in Foraminifera fossils over time, to more closely pinpoint events during the PETM. "In sediment records, when you look at the ratio of carbon-12 to carbon-13 in a particular species, you see that it's stable and then it abruptly shifts, wiggles back and forth and slowly returns to pre-event values over hundreds of thousands of years," Schaller said. "This evidence defines the event, and tells us that the atmosphere changed, in particular adding carbon from a source depleted in carbon-13. A comet impact on its own may have contributed carbon to the atmosphere, but is too small to explain the whole event and more likely acts as a trigger for additional carbon releases from other sources." As a source of fossils, the team used sediment cores - cylinders of sediment extracted vertically from sediment deposits with a hollow bit - known to correspond to the time period of the PETM. Sediments near the top are more recent, those further down are older, and signature layers indicating known events are used to calibrate the timescale represented in the sample. The team chose cores from three sites - Wilson Lake and Millville in New Jersey, and Blake Nose, an underwater site east of Florida - known for a rich sedimentary record of the time period. As Schaller tells it, the discovery of microtektites was "completely by accident." Ordinarily, the team passes samples through sieves of various sizes, to isolate samples most likely to contain forams. The tektites, which are smaller than most forams, would have been largely removed in
[meteorite-list] Chinese Meteorite Field Likely To Be World's Largest
http://gbtimes.com/china/chinese-meteorite-field-likely-be-worlds-largest Chinese meteorite field likely to be world's largest gbtimes October 14, 2016 Experts from the Chinese Academy of Sciences confirmed on October 13 that the meteorite-strewn field in Xinjiang Uyghur Autonomous Region is likely the world's largest. According to a report by Xinhua News Agency, the field of meteorites stretches to an estimated 425 kilometres, 150 kilometres larger than the Gibeon meteorite shower in Namibia. The shower has been named Altay, after the region in which it landed. First discovered in 1898, the 28-tonne Armanty meteorite was originally thought to be isolated, until the 430-kilogramme Ulasitai meteorite was discovered 100 years later. However, Shanghai Daily reports that it was not until 2011 that a third - the 5-tonne Wuxilike - was found that scientists noticed that all three were in a line stretched across 425 kilometres. "This suggests that the meteorites were all from the same parent asteroid before it separated as it entered the Earth's atmosphere," said Xu Weibiao, meteorite curator with the observatory under the Chinese Academy of Sciences. __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Journal - September 27, 2016
http://dawn.jpl.nasa.gov/mission/journal_09_27_16.html
Dawn Journal
Dr. Marc Rayman
September 27, 2016
Dear Dawnniversaries,
Nine years ago today, Dawn set sail on an epic journey of discovery and
adventure. The intrepid explorer has sailed the cosmic seas and collected
treasures that far exceeded anything anticipated or even hoped for. It
began its voyage at Earth with a fiery ascent atop a Delta rocket. After
escaping from its home planet's gravitational grasp, it flew through
the solar system perched on a pillar of blue-green xenon ions that enabled
the probe to accomplish a mission that would have been impossible with
conventional propulsion. In 2009, with its sights set on more distant
lands, Dawn swept past Mars, taking some of the planet's orbital
energy for its own. By its fourth anniversary, Dawn was conducting an
extensive orbital investigation of protoplanet Vesta, the second most
massive resident of the main asteroid belt. Dawn found it to be quite
unlike typical asteroids. Rather than a big chunk of rock, Vesta is like
a small planet, and scientists recognize it as being more closely related
to the rocky planets of the inner solar system (including Earth) than
to the much smaller asteroids. Vesta's nearer brethren are the blue
and white planet where Dawn began its mission nine years ago and the red
one it flew by 17 months later. By its fifth anniversary of leaving Earth,
the interplanetary spaceship was on its way to yet another distant, alien
world. Under the careful guidance of its human colleagues, Dawn completed
its 2.5-year journey from Vesta to Ceres last year. Now a perpetual companion
of the first dwarf discovered, the veteran space traveler will spend all
future anniversaries in orbit around Ceres, even after its operational
lifetime has concluded.
By February of this year, the spacecraft had exceeded all of its original
objectives established by NASA. Doing so involved orbiting Vesta for 14
months and, at that time, Ceres for almost a year. On June 30, Dawn's
prime mission concluded, and on July 1, its "extended mission" began.
[Dawn LAMO Image 147]
This simulated view of Ahuna Mons, Ceres' highest mountain, was made
with bonus stereo pictures Dawn acquired from an altitude of 240 miles
(385 kilometers). Ahuna Mons is likely a cryovolcano ("cold volcano"),
formed by cryomagma composed of salty mud rising from underground. The
volcano is geologically young, probably between 50 and 240 million years.
(We discussed in May how ages are estimated, but the analysis for Ahuna
Mons cannot yet pin down the age more accurately.) As Ceres is nearly
4.6 billion years old, a structure that developed so recently suggests
that some of the conditions that were necessary may persist even today.
(So far, scientists have identified no other cryovolcanoes on Ceres.)
It took somewhere between a few hundred and few hundred thousand years
for the volcano to build up to its present size. The elevation of the
summit is about 13,000 feet (4,000 meters), and the mountain is 11 miles
(17 kilometers) across at the base. Note the streaks from rockfalls down
the steep slopes (about 35 degrees). This view is from the north, and
in the foreground is a crater coincidentally 11 miles (17 kilometers)
across. From the lowest point in this crater to the top of the volcano
is 24,800 feet (7,560 meters) vertically across a horizontal distance
of only nine miles (15 kilometers). With 2.7 percent of Earth's gravity,
this could be a very nice extraterrestrial hike.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
One year ago today, the ship was in its third Ceres mapping orbit, scrutinizing
the exotic landscapes 915 miles (1,470 kilometers) beneath it. Less than
four weeks later, it started powering its way down through the uncharted
depths of Ceres gravitational field to undertake the final planned observations
of its long mission.
When ion thrusting concluded on Dec. 13, 2015, Dawn was orbiting closer
to Ceres than the International Space Station is to Earth. From its vantage
point only 240 miles (385 kilometers) high, the probe used its suite of
sophisticated sensors to develop a richly detailed portrait of the only
dwarf planet in the inner solar system. Dawn's reason for venturing
to its fourth mapping orbit was to collect about 35 days of neutron spectra,
35 days of gamma-ray spectra and 20 days of gravity measurements. Given
the complexity of operating in the low, tight orbit, mission planners
expected it could take about three months to acquire these precious data
and transmit them to Earth. Operations turned out to be essentially flawless,
and by the time Dawn left that orbit on Sept. 2, it had accumulated 183
days of neutron spectra, 183 days of gamma-ray spectra and 165 days of
gravity measurements. In addition, the spacecraft amassed a sensational
bonus of 38,000 high resolution photos (including stereo and color) as
well as more than 11
[meteorite-list] Mars Rover Opportunity Update: September 20-26, 2016
http://mars.nasa.gov/mer/mission/status.html#opportunity OPPORTUNITY UPDATE: Busy Week of Science and Imaging for Opportunity - sols 4500 - 4506, September 20, 2016-September 26, 2016: Since leaving the "Lewis and Clark Gap" of Marathon Valley, Opportunity has been driving through "Bitterroot valley" toward her first waypoint of the new extended mission, "Spirit Mound." With the Sol 4500 (Sept. 20, 2016) drive, she arrived at the base of the mound. The rover then bumped to a parking position for imaging and access to possible surface targets on Sol 4502 (Sept. 22, 2016). Finally, on Sol 4505 (Sept. 25, 2016), Opportunity bumped to "Gasconade," a thin, bright and linear outcrop, another possible surface target. The Sol 4500 uplink had to be shortened to avoid an X-band fault due to a very late X-band pass and Earth set below the highly tilted rover deck. A Quick Fine Attitude (QFA) was also done on Sol 4500. Panoramic Camera (Pancam) images of Spirit Mound and a Navigation Camera (Navcam) panorama were done on Sol 4501 (Sept. 21, 2016), with dust devil monitoring the following morning. On Sol 4502 (Sept. 22, 2016) Pancam images of nearby boulders were taken before the drive and a post-drive Pancam mosaic of Spirit Mound was taken afterwards. Opportunity took more color Pancam images of Spirit Mound, performed a Pancam low sun survey, and took Microscopic Imager (MI) sky flats on Sol 4503 (Sept. 23, 2016), with a Pancam horizon survey the following morning. On Sol 4504 (Sept. 24, 2016), Opportunity took a 13-filter Pancam image of "Council Bluffs", a section of the ridge south of Gasconade, and Gasconade itself, followed by a Pancam 4x1 context panorama of the ridgeline including Council Bluffs. On Sol 4506 (Sept. 26, 2016), Opportunity collected a Navcam image of her tracks, took a Pancam image of "Portland," a breccia target, and a Pancam mosaic of the top of Spirit Mound above Gasconade. As of Sol 4506 (Sept. 26, 2016), the solar array energy production is 474 watt-hours with an elevated atmospheric opacity (Tau) of 0.892 and a solar array dust factor of 0.701. Total odometry as of Sol 4505 (Sept. 25, 2016) is 26.99 miles (43.44 kilometers). __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Curiosity Rover Finds Evidence of Mars Crust Contributing to Atmosphere
http://www.jpl.nasa.gov/news/news.php?feature=6631 Curiosity Finds Evidence of Mars Crust Contributing to Atmosphere Jet Propulsion Laboratory September 29, 2016 NASA's Curiosity rover has found evidence that chemistry in the surface material on Mars contributed dynamically to the makeup of its atmosphere over time. It's another clue that the history of the Red Planet's atmosphere is more complex and interesting than a simple legacy of loss. The findings come from the rover's Sample Analysis at Mars, or SAM, instrument suite, which studied the gases xenon and krypton in Mars' atmosphere. The two gases can be used as tracers to help scientists investigate the evolution and erosion of the Martian atmosphere. A lot of information about xenon and krypton in Mars' atmosphere came from analyses of Martian meteorites and measurements made by the Viking mission. "What we found is that earlier studies of xenon and krypton only told part of the story," said Pamela Conrad, lead author of the report and SAM's deputy principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "SAM is now giving us the first complete in situ benchmark against which to compare meteorite measurements." Of particular interest to scientists are the ratios of certain isotopes - or chemical variants - of xenon and krypton. The SAM team ran a series of first-of-a-kind experiments to measure all the isotopes of xenon and krypton in the Martian atmosphere. The experiments are described in a paper published in Earth and Planetary Science Letters. The team's method is called static mass spectrometry, and it's good for detecting gases or isotopes that are present only in trace amounts. Although static mass spectrometry isn't a new technique, its use on the surface of another planet is something only SAM has done. Overall, the analysis agreed with earlier studies, but some isotope ratios were a bit different than expected. When working on an explanation for those subtle but important differences, the researchers realized that neutrons might have gotten transferred from one chemical element to another within the surface material on Mars. The process is called neutron capture, and it would explain why a few selected isotopes were more abundant than previously thought possible. In particular, it looks as if some of the barium surrendered neutrons that got picked up by xenon to produce higher-than-expected levels of the isotopes xenon-124 and 126. Likewise, bromine might have surrendered some of its neutrons to produce unusual levels of krypton-80 and krypton-82. These isotopes could have been released into the atmosphere by impacts on the surface and by gas escaping from the regolith, which is the soil and broken rocks of the surface. "SAM's measurements provide evidence of a really interesting process in which the rock and unconsolidated material at the planet's surface have contributed to the xenon and krypton isotopic composition of the atmosphere in a dynamic way," said Conrad. The atmospheres of Earth and Mars exhibit very different patterns of xenon and krypton isotopes, particularly for xenon-129. Mars has much more of it in the atmosphere than does Earth. "The unique capability to measure in situ the six and nine different isotopes of krypton and xenon allows scientists to delve into the complex interactions between the Martian atmosphere and crust," said Michael Meyer, lead scientist for the Mars Exploration Program at NASA Headquarters in Washington. "Discovering these interactions through time allows us to gain a greater understanding of planetary evolution." NASA's Mars Science Laboratory Project is using Curiosity to determine if life was possible on Mars and study major changes in Martian environmental conditions. NASA studies Mars to learn more about our own planet, and in preparation for future human missions to Mars. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate in Washington. For more information about SAM, visit: http://ssed.gsfc.nasa.gov/sam SAM experiment data are archived in the Planetary Data System, online at: http://pds.nasa.gov For more information about Curiosity, visit: http://www.nasa.gov/msl The research paper is available at: http://dx.doi.org/10.1016/j.epsl.2016.08.028 News Media Contact Written by Elizabeth Zubritsky Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 guy.webs...@jpl.nasa.gov Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2016-249 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com
[meteorite-list] Farewell Rosetta: ESA Mission to End on Comet Surface
http://www.jpl.nasa.gov/news/news.php?feature=6633 Farewell Rosetta: ESA Mission to End on Comet Surface Jet Propulsion Laboratory September 29, 2016 The European Space Agency's (ESA) Rosetta mission will come to a dramatic end on Friday, Sept. 30, with a controlled touchdown of the spacecraft on a region of comet 67P/Churyumov-Gerasimenko known for active pits that spew comet dust into space. Confirmation of the end of mission is expected at about 4:20 a.m. PDT (7:20 a.m. EDT). ESA is ending the mission due to the spacecraft's ever-increasing distance from the sun, which has resulted in significantly reduced solar power with which to operate the vehicle and its instruments. Rosetta is an international mission led by ESA with instruments provided by its member states, and additional support and instruments provided by NASA. "The European Space Agency's Rosetta Mission is a magnificent demonstration of what excellent mission design, execution, and international collaboration can achieve," said Geoff Yoder, acting associate administrator for NASA's Science Mission Directorate in Washington. "Being neighbors with a comet for more than two years has given the world invaluable insight into these beautiful nomads of deep space. We congratulate ESA on its many accomplishments during this daring mission." The final hours of descent will enable Rosetta to make many once-in-a-lifetime measurements, including analyzing gas and dust closer to the surface than ever possible before, and taking very high-resolution images of the comet nucleus. The images will include views of the open pits of the Ma'at region, where the spacecraft is expected to make its controlled impact. Ma'at is home to several active pits more than 330 feet (100 meters) in diameter and 160 to 200 feet (50 to 60 meters) deep. The walls of the pits exhibit intriguing lumpy structures about 3 feet wide (1 meter wide) called "goose bumps." Scientists believe those structures could be the signatures of early cometesimals that assembled to create the comet in the early phases of solar system formation. Rosetta will attempt to get its closest look yet at these fascinating structures on Sept. 30, when the spacecraft will target a point adjacent to a 430-feet-wide (130-meter), well-defined pit that the mission team has informally named Deir el-Medina. "Rosetta will keep giving us data to the very end," said Bonnie Buratti, project scientist for the U.S. Rosetta project from NASA's Jet Propulsion Laboratory in Pasadena, California. "NASA's three instruments aboard Rosetta will be among those collecting data all the way down." Those three NASA science instruments are: the Microwave Instrument for Rosetta Orbiter (MIRO); an ultraviolet spectrometer called Alice; and the Ion and Electron Sensor (IES). They are part of a suite of 11 science instruments on the orbiter. MIRO was designed to provide data on how gas and dust leave the surface of the nucleus to form the coma and tail that give comets their intrinsic beauty. Studying the surface temperature and evolution of the coma and tail provides information on how the comet evolves as it approaches and leaves the vicinity of the sun. MIRO has the ability to study water, carbon monoxide, ammonia and methanol. Alice, an ultraviolet spectrometer, analyzes gases in the comet's coma and tail; measures how fast the comet produces water, carbon monoxide and carbon dioxide (clues to the surface composition of the nucleus); and measures argon levels. These measurements help determine the temperature of the solar system when the nucleus formed more than 4.6 billion years ago. The Ion and Electron Sensor is part of a suite of five instruments that analyzes the plasma environment of the comet, particularly the coma. The instrument measures the charged particles in the sun's outer atmosphere, or solar wind, as they interact with the gas flowing out from the comet. NASA provided part of the electronics package for the Double Focusing Mass Spectrometer, which is part of the Swiss-built Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument. U.S. scientists also partnered on several non-U.S. instruments and were involved in seven of the mission's 26 instrument collaborations. NASA's Deep Space Network is supporting ESA's Ground Station Network for spacecraft tracking and navigation. NASA also provided autonomous science operations planning software, which helped in planning science operations and navigation support. The Rosetta mission was launched in 2004 and arrived at comet 67P/Churyumov-Gerasimenko on Aug. 6, 2014. It's the first mission in history to rendezvous with a comet and escort it as it orbits the sun. On Nov. 4, 2014, a smaller lander named Philae -- which had been deployed from the Rosetta mothership -- touched down on the comet and bounced several times before alighting on the surface. Philae obtained the first images
[meteorite-list] NASA TV Coverage of European Mission Comet Touchdow (Rosetta)
http://www.jpl.nasa.gov/news/news.php?feature=6630 NASA TV Coverage of European Mission Comet Touchdown Jet Propulsion Laboratory September 28, 2016 NASA Television and the agency's website will air the conclusion of ESA's (European Space Agency's) Rosetta mission from 3:15 to 5 a.m PDT (6:15 to 8 a.m. EDT) Friday, Sept. 30, with NASA commentary, interviews and analysis of the successful mission. The Rosetta mission will end with the controlled descent of the spacecraft onto the surface of comet 67P/Churyumov-Gerasimenko at around 4:20 a.m. PDT (7:20 a.m. EDT). Rosetta was launched in 2004 carrying 11 science instruments, with several contributions from NASA including: the Microwave Instrument for Rosetta Orbiter (MIRO); the Alice spectrograph; the Ion and Electron Sensor (IES); and the Double Focusing Mass Spectrometer (DFMS) electronics package for the Rosetta Orbiter Spectrometer for Ion Neutral Analysis (ROSINA). NASA's Deep Space Network supports ESA's Ground Station Network for spacecraft tracking and navigation. The spacecraft arrived at its destination comet on Aug. 6, 2014, becoming the first mission in history to rendezvous with a comet and escort it as it orbits the sun. About two months later, the small Philae lander deployed from Rosetta touched down on the comet and bounced several times before alighting on the surface. Philae obtained the first images ever taken from the surface of a comet, and sent back valuable scientific data for several days. ESA is ending the mission because the spacecraft's ever-increasing distance from the sun has resulted in significantly reduced solar power to operate the spacecraft and its instruments. Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta is the first spacecraft to witness up close how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in the formation of planets. In addition to NASA's contribution, Rosetta's Philae lander was provided by a consortium led by the German Aerospace Center, Max Planck Institute for Solar System Research, French National Space Agency, and Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena, California, manages the U.S. contributions to the Rosetta mission for the agency's Science Mission Directorate in Washington. JPL also built the MIRO and hosts its principal investigator, Mark Hofstadter. The Southwest Research Institute developed Rosetta's IES and Alice instruments and hosts their principal investigators, James Burch for IES and Alan Stern for the Alice instrument. NASA TV streaming video, downlink and updated scheduling information is at: http://www.nasa.gov/nasatv The landing coverage will also be streamed live at: http://www.ustream.tv/nasajpl2 For more information on the U.S. instruments aboard Rosetta, visit: http://rosetta.jpl.nasa.gov News Media Contact DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 a...@jpl.nasa.gov Dwayne Brown / Laurie Cantillo NASA Headquarters, Washington 202-358-1726 / 202-358-1077 dwayne.c.br...@nasa.gov / laura.l.canti...@nasa.gov 2016-248 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
