[meteorite-list] Mars Rover Investigates Signs of Steamy Martian Past
http://www.jpl.nasa.gov/news/news.cfm?release=2007-144 Mars Rover Investigates Signs of Steamy Martian Past December 10, 2007 SAN FRANCISCO - Researchers using NASA's twin Mars rovers are sorting out two possible origins for one of Spirit's most important discoveries, while also getting Spirit to a favorable spot for surviving the next Martian winter. The puzzle is what produced a patch of nearly pure silica -- the main ingredient of window glass -- that Spirit found last May. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic steam rises through cracks. On Earth, both of these types of settings teem with microbial life. Whichever of those conditions produced it, this concentration of silica is probably the most significant discovery by Spirit for revealing a habitable niche that existed on Mars in the past, said Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the rovers' science payload. The evidence is pointing most strongly toward fumarolic conditions, like you might see in Hawaii and in Iceland. Compared with deposits formed at hot springs, we know less about how well fumarolic deposits can preserve microbial fossils. That's something needing more study here on Earth. Halfway around Mars from Spirit, Opportunity continues adding information about types of wet environments on ancient Mars other than hot springs or fumaroles. It is examining layers exposed inside a crater, but still near the top of a stack of sulfate-rich layers hundreds of meters (yards) thick. Scientists read a history of conditions that evolved from wetter to drier, based on findings by Opportunity and observations of the region by Mars orbiters. The solar-powered rovers have been active on Mars since January 2004, more than 15 times longer than originally planned. Their third Martian winter will not reach minimum sunshine until June, but Spirit already needs two days of power output to drive for an hour. Spirit is going into the winter with much more dust on its solar panels than in previous years, said John Callas of NASA's Jet Propulsion Laboratory, Pasadena, Calif., project manager for the rovers. The last Martian winter, we didn't move Spirit for about seven months. This time, the rover is likely to be stationary longer and with significantly lower available energy each Martian day. Dust storms that darkened Martian skies this past June dropped dust onto both rovers. However, gusts cleaned Opportunity's panels, and Opportunity is closer to the equator than Spirit is, so concerns for winter survival focus on Spirit. The team has selected a sun-facing slope of about 25 degrees on the northern edge of a low plateau, Home Plate, as a safe winter haven for Spirit. Both rovers resumed productive field work after the June dust storms. Spirit explored the top of Home Plate, in the vicinity of silica-rich soil it discovered before the dust storms hit. This stuff is more than 90 percent silica, Squyres said. There aren't many ways to explain a concentration so high. One way is to selectively remove silica from the native volcanic rocks and concentrate it in the deposits Spirit found. Hot springs can do that, dissolving silica at high heat and then dropping it out of solution as the water cools. Another way is to selectively remove almost everything else and leave the silica behind. Acidic steam at fumaroles can do that. Scientists are still assessing both possible origins. One reason Squyres favors the fumarole story is that the silica-rich soil on Mars has an enhanced level of titanium. On Earth, titanium levels are relatively high in some fumarolic deposits. Mineral mapping and high-resolution imagery from Mars orbiters are helping scientists put the findings of Spirit and Opportunity into broader geological context. Opportunity's exploration of the Meridiani region has taken advantage of the natural excavations at impact craters to inspect layers extending several meters below the surface of the regional plain. These sulfate-rich layers bear extensive evidence for a wet, acidic past environment. They are a small upper fraction of the sulfate-rich layering exposed elsewhere in Meridiani and examined from orbit. We see evidence from orbit for clay minerals under the layered sulfate materials, said Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the rovers' science payload. They indicate less acidic conditions. The big picture appears to be a change from a more open hydrological system, with rainfall, to more arid conditions with groundwater rising to the surface and evaporating, leaving sulfate salts behind. JPL, a division of California Institute of Technology, Pasadena, manages the rovers for NASA's Science Mission Directorate. For images and information about the rovers, visit: www.nasa.gov/rovers and http://marsrovers.jpl.nasa.gov .
[meteorite-list] 1st Meeting of the International Primitive Body Exploration Working Group (IPEWG)
http://www.jspec.jaxa.jp/okinawa_index.html The First Meeting of The International Primitive Body Exploration Working Group (IPEWG) January 14-15, 2006 Okinawa, Japan [ATTENTION] A Possible Extension of the Meeting until January 16th Thanks to strong responces received by now, we are cyrrently invetigating a possibility to extend the meeting for one more day, i.e., to continue until Januray 16th. Please be warned and plan your travel schedule carefully. We will update this page as soon as such an schedule extension is decided and we will send emails to all those who have registered by then. Scope Thanks to successful development of enabling technologies for deep space exploration, missions to small solar system bodies have revolutionized our understandingof the Solar System's origin and evolution in the last decade. At present, rendezvous, impact, landing and sample return missions to asteroids and comets such as NEAR-Shoemaker, Hayabusa, Stardust, Deep Impact, Rosetta,Dawn, EPOXI and NEXT as well as New Horizons, a fly-by mission to EKBOs, are completed or still in the middle of operation. Also more challenging, new missions are under development or under concept studies by several space agencies including Hayabusa-2, Hayabusa Mk-II(Marco Polo), Don Quijote, OSIRIS, and Phobos-Grunt. In addition to scientific and engineering motivations, NEO studies receive increasing interests in the context of planetary defense, deep space human spaceflight and potential in-situ resource utilization. In 1980's, the inter-agency coordination group for Comet Halley exploration proved that synergy of coordinated individual missions could enrich total outcomes more than each result combined.Since then, international exploration working groups participated by international space agencies have been formed and played key roles for advancing fields of solar terrestrial physics, Moon and Mars missions. As we are entering the second golden age of the primitive body exploration in upcoming decade, now is the appropriate time to create the International Primitive Body Exploration Working Group (IPEWG) in order to promote international collaborations and to maximize outcomes of each mission. With these in mind, the first IPEWG meeting will be hosted by JAXA at Okinawa,the southern-most, tropical island in Japan. All space agencies, scientists, engineers and other interested stakeholders are cordially invited. JSPEC Program Office : [EMAIL PROTECTED] Japan Aerospace Exploration Agency(JAXA) JAXA Space Exploration Center(JSPEC) 3-1-1 Yoshinodai, Sagamihara, Kanagawa. 229-8510, JAPAN Fax. +81-42-759-8675 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] SMART-1: Travel Maps of the Lunar North Pole
http://www.esa.int/esaCP/SEMMH029R9F_index_0.html SMART-1: Travel maps of the lunar north pole European Space Agency 5 December 2007 A new map obtained with SMART-1 data shows the geography and illumination of the lunar north pole. Such maps will be of great use for future lunar explorers. The lunar poles are very interesting for future science and exploration of the Moon mainly because of their exposure to sunlight. They display areas of quasi-eternal light, have a stable thermal environment and are close to dark areas that could host water ice â potential future lunar base sites. The SMART-1 north pole map, covering an area of about 800 by 600 km, shows geographical locations of some craters of interest. Peary is a large impact crater closest to the north pole. At this latitude the interior of the crater receives little sunlight, but SMART-1 was able to observe it during phases when the crater floor was sufficiently illuminated for imaging. A previous lunar mission, the U.S. Clementine, observed the Peary crater during the north summer, and identified some areas particularly illuminated by the sun in that season. With its Advanced Moon Imaging Experiment (AMIE) micro-camera, SMART-1 has complemented this data set by identifying the areas that are also well-illuminated during northern winter. [SMART-1 north pole travel map] Solar illumination makes these areas ideal for robotic outposts or lunar bases making use of solar power, says ESA's SMART-1 Project Scientist, Bernard Foing. Hermite is another lunar impact crater located along the northern lunar limb, close to the north pole of the Moon. Looking from Earth, it is viewed nearly from the side, illuminated by oblique sunlight. Crater Plaskett is located on the northern far-side of the Moon, about 200 km from the north pole. It receives sunlight at a low angle. Because of the isolation of this crater and its location near the lunar limb, it has been suggested as a possible additional site of a future lunar base that could be used to simulate isolated conditions during a manned mission to Mars. From the crater rim, rovers could be sent out to explore nearby craters which are permanently in shadow and may contain water ice. If the layers of ice come from the volatiles deposited by comets and water-rich asteroids, we could better understand how, and how much, water and organic material was delivered to Earth over its history, said Foing. Notes for editors: These images were analysed in the framework of a study project for the design and operations of lunar polar robotic landers and rovers, by Marina Ellouzi, a Master's student in space engineering at the Paris-Meudon Observatory. The polar mosaics were presented and discussed at the 9th ILEWG International lunar conference in October 2007. For more information: Bernard Foing, ESA SMART-1 Project Scientist Email: Bernard.Foing @ esa.int Jean - Luc Josset, SMART-1 AMIE Principal Investigator, Space-X Space Exploration Institute Email : Jean-Luc.Josset @ space-x.ch __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Arctic Impact Crater Lake Reveals Interglacial Cycles in Sediments
http://dailyheadlines.uark.edu/11974.htm FOR RELEASE: Tuesday, December 11, 2007 Arctic Impact Crater Lake Reveals Interglacial Cycles in Sediments Univerity of Arkansas FAYETTEVILLE, Ark. - A University of Arkansas researcher and a team of international scientists have taken cores from the sediments of a Canadian Arctic lake and found an interglacial record indicating two ice-free periods that could pre-date the Holocene Epoch. Sonja Hausmann, assistant professor of geosciences in the J. William Fulbright College of Arts and Sciences at the University of Arkansas, and her colleagues will report their preliminary findings at the American Geophysical Union meeting this week. The researchers traveled by increasingly smaller planes, Ski-doos and finally sleds dragged on foot to arrive at the Pingualuit Crater, located in the Parc National des Pingualuit in northern Quebec. The crater formed about 1.4 million years ago as the result of a meteorite impact, and today it hosts a lake about 267 meters deep. Its unique setting - the lake has no surface connection to other surrounding water bodies - makes it a prime candidate for the study of lake sediments. Scientists study lake sediments to determine environmental information beyond historical records. Hausmann studies diatoms, unicellular algae with shells of silica, which remain in the sediments. Diatoms make excellent bioindicators, Hausmann said, because the diatom community composition changes with environmental changes in acidity, climate, nutrient availability and lake circulation. By examining relationships between modern diatom communities and their environment, Hausmann and her colleagues can reconstruct various historic environmental changes quantitatively. However, most sediments of lakes in previously glaciated areas have limitations - they only date back to the last ice age. Glaciers are powerful. They polish everything, Hausmann said. Glaciers typically carve out any sediments in a lake bed, meaning any record before the ice age is swept away. However, the unique composition of the Pingualuit Crater Lake led Michel A. Bouchard to speculate in 1989 that the sediments beneath its icy exterior might have escaped glacial sculpting. So in May of this year, Hausmann and her colleagues donned parkas, hauled equipment on ski-doos and slogged through sub-zero temperatures for three weeks so they could core sediments and collect data from the lake. They carefully carved squares of ice out to make a small hole for equipment, then began a series of investigations that included pulling up a core of the topmost 8.5 meters of sediment. An echosounder indicated that the lake bottom may have more than 100 meters of relatively fine-grained sediments altogether. During the time since the expedition, researchers have examined the physical, magnetic and sedimentological properties of the sediment core. The sediment core contains mostly faintly laminated silts or sandy mud with frequent pebble-size rock fragments, which is typical of deposits found in water bodies covered by an ice sheet. Sandwiched in the middle of the faintly laminated silts and sandy mud, the researchers found two distinct and separate layers containing organically rich material that most likely date back well before the Holocene, representing earlier ice-free periods. The samples they found contain the remains of diatoms and other organic material, suggesting that they represent ice-free conditions and possibly interglacial periods. There are no paleolimnological studies of lakes that cover several warm periods in this area, Hausmann said. The terrestrial record will be complementary to marine records or to long ice-core records from Greenland. The international team of researchers in the field included Guillaume St-Onge; Reinhard Pienitz, principal investigator; Veli-Pekka Salonen of the University of Helsinki, Finland; and Richard Niederreiter, coring expert. Please visit http://www.cen.ulaval.ca/pingualuit/index.html for more information. ### Contact: Sonja Hausmann, assistant professor, geosciences J. William Fulbright College of Arts and Sciences (479) 575-6419, [EMAIL PROTECTED] Melissa Lutz Blouin, director of science and research communications University Relations (479) 575-, [EMAIL PROTECTED] __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] The Best Way to Deflect an Asteroid
http://www.nytimes.com/2007/12/09/magazine/09_5_asteroid.html?_r=1oref=slogin The Best Way to Deflect an Asteroid By LIA MILLER New York Times December 9, 2007 In 1908, an asteroid is thought to have entered the earth's atmosphere and exploded over a Siberian forest, leveling some 800 square miles of trees in what is known as the Tunguska Event. If we knew today that another asteroid were on a path to intersect with our planet, what could we do? Massimiliano Vasile, a lecturer in aerospace engineering at the University of Glasgow, recently concluded a two-year study comparing nine asteroid-deflection methods, rating them for efficiency, complexity and launch readiness. The best method, called mirror bees, entails sending a group of small satellites equipped with mirrors 30 to 100 feet wide into space to 'swarm around an asteroid and trail it, Vasile explains. The mirrors would be tilted to reflect sunlight onto the asteroid, vaporizing one spot and releasing a stream of gases that would slowly move it off course. Vasile says this method is especially appealing because it could be scaled easily: 25 to 5,000 satellites could be used, depending on the size of the rock. The losing ideas - satellites equipped with lasers; detonating a nuclear explosion; pushing the asteroid with a spacecraft, to name a few - might still have their place. Vasile says improved technologies could make others appealing in the future. (In March, NASA released a report on near Earth objects that deemed the nuclear-explosion method the most effective.) Michael Gaffey, professor of space studies at the University of North Dakota, says the risk of dying from an asteroid strike is about 1 in 2 million. The problem is that the consequences are tremendous; a half-mile-wide asteroid or larger, of which there are more than 700 that come close to Earth's orbit, could have an impact equal to 60 billion tons of TNT. While it is not likely to happen, you still want to be prepared. You don't panic, you don't have to run around screaming and waving your hands, Gaffey says. But you do need to devote resources to it. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - December 12, 2007
MARS RECONNAISSANCE ORBITER HIRISE IMAGES December 12, 2007 o Basal Exposure of the South Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_006243_0975 o Wrinkle Ridges in Hesperia Planum http://hirise.lpl.arizona.edu/PSP_006223_1600 o Fractures and Grooves in South Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_006151_0975 o Sand and Rock in Meridiani Planum http://hirise.lpl.arizona.edu/PSP_006148_1820 o Complex Folded Terrain on the Floor of Hellas Basin http://hirise.lpl.arizona.edu/PSP_006133_1410 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mammoths Found Peppered with Meteorite Fragments
http://news.bbc.co.uk/2/hi/science/nature/7130014.stm Great beasts peppered from space By Jonathan Amos BBC News December 11, 2007 Startling evidence has been found which shows mammoth and other great beasts from the last ice age were blasted with material that came from space. Eight tusks dating to some 35,000 years ago all show signs of having being peppered with meteorite fragments. The ancient remains come from Alaska, but researchers also have a Siberian bison skull with the same pockmarks. The scientists released details of the discovery at a meeting of the American Geophysical Union in San Francisco, US. They painted a picture of a calamitous event over North America that may have severely knocked back the populations of some species. Blast direction We think that there was probably an impact which exploded in the air that sent these particles flying into the animals, said Richard Firestone from the Lawrence Berkeley National Laboratory. In the case of the bison, we know that it survived the impact because there's new bone growth around these marks. And geoscience consultant Allen West added: If the particles had gone through the skin, they may not have made it through to vital organs; but this material could certainly have blinded the animals and severely injured them. The mammoth and bison remains all display small (about 2-3mm in size) perforations. Raised, burnt surface rings trace the point of entry of high-velocity projectiles; and the punctures are on only one side, consistent with a blast coming from a single direction. Viewed under an electron microscope, the embedded fragments appear to have exploded inside the tusk and bone, say the researchers. Shards have cut little channels. The sunken pieces are also magnetic, and tests show them to have a high iron-nickel content, but to be depleted in titanium. The ratios of different types of atoms in the fragments meant it was most unlikely they had originated on Earth, the team told the AGU meeting. Magnetic hunt The discovery follows on from the group's previous research which claimed a more recent space collision - some 13,000 years ago. The researchers reported the discovery of sediment at more than 20 sites across North America that contained exotic materials: tiny spheres of glass and carbon, ultra-small specks of diamond and amounts of the rare element iridium that were too high to be terrestrial. The scientists also found a black layer which, they argued, was the charcoal deposited by wildfires that swept the continent after the space object smashed into the Earth's atmosphere. It was just a tiny magnet on a string, but very strong. It would swing over and stick firmly to these little dots Allen West We had found evidence of particle impacts in chert, or flint, at a Clovis Indian site in Michigan, Dr Firestone said. So, we got the idea that if these impacts were in the chert, then they might likely also have occurred in large surfaces such as tusks; and we decided it was worth a shot to go look for them. Allen West began the hunt at a mammoth tusk sale in his home state of Arizona. He immediately found one tusk with the tell-tale pockmarks and asked the trading company if he could look through its entire collection. He sorted literally thousands of items. There are many things that can cause spots, such as algae, and there were a few of those; but I was only interested in the ones that were magnetic, he recalled. It was just a tiny magnet on a string, but very strong. It would swing over and stick firmly to these little dots. The search turned up a further seven ivory specimens of interest, together with the bison skull. Further clues But having gone out and tested the hypothesis of tusk impacts, and having apparently uncovered such items - the team was then astonished to find the animal remains were about 20,000 years older than had been anticipated. The researchers are now considering a number of possibilities - one that could even tie the older remains to the younger event. People who collect these items today in Siberia and Alaska frequently find the tusks sticking out of the permafrost or eroding out of a riverbank, explained Mr West. Maybe, these were tusks from dead animals that were just exposed on the surface, so when this thing blew up in the atmosphere, it would have peppered them. The date could really be anywhere from 13,000 to 35-40,000 years ago. The team believes there must still be peppered tusks out there that can be dated to 13,000 years ago, and the hope is that the AGU presentation will prompt museums and collectors to look through their archives. There should also be a layer of this same meteoritic material in the sedimentary record. It's probably very thin. If we can locate the right place and it hasn't been turbated, we should be able to find this layer; and it shouldn't be too different from the impact layer we found for the 13,000-year event, said Dr Firestone. Neither proposed
[meteorite-list] First Recorded Meteor Strike in US Fell 200 Years Ago (Weston Meteorite)
http://www.stamfordadvocate.com/news/local/scn-sa-meteorite1dec12,0,1063724.story First recorded meteor strike in the U.S. slammed into area 200 years ago By Tim Stelloh The Advocate December 12 2007 NEW HAVEN - The 28-pound rock on the third floor of the Yale Peabody Museum isn't much to look at. It's about the size of a cinder block, with jagged edges and a rusty hue that, beneath the glint of a Plexiglas case, shimmers when viewed from the right angle. The rock is no ordinary remnant of glacial boulders, a common find in Connecticut. It is a piece of meteorite that, shortly after 6 a.m. on a cloudy morning 200 years ago this Friday, flashed through the sky in a ball of fire, producing a sonic boom that shook people out of their beds and rained fragments of nickel and iron across a 10-mile strip of what is now Easton and Monroe, but at the time was Weston. The rock, recovered from Tashua Hill in Trumbull, is the largest of at least six fragments of the first recorded meteorite to hit the United States. It revolutionized our understanding of the universe, said Karl Turekian, a professor of geology and geophysics at Yale. Meteorites like Weston . . . give us the age of the Earth, the composition of the solar system. The story of the meteorite and subsequent scientific discoveries will be commemorated Friday with events at Easton Public Library and Weston High School. Most meteorites are fragments from the asteroid belt between Jupiter and Mars. Some, like the Cape York meteorite, which weighed in at 200 tons when it exploded in the atmosphere thousands of years ago, are massive. The Weston meteorite was far smaller - though in an article published in the years after the collision by Benjamin Silliman, the Yale scientist who investigated it and interviewed witnesses, described that early morning flash of fire as one-half to two-thirds the size of the moon. In the clear sky a brisk scintillation was observed about the body of the meteor, like that of a burning firebrand carried against the wind, he wrote in the American Journal of Science and Arts. The flash was seen from as far north as Rutland, Vt., and as far south as New Jersey, Silliman wrote. There were explosions. There were whizzing and roaring sounds. Some who saw and heard the meteorite thought it was a tornado, Silliman wrote. Others compared the sound to gunfire or to a wagon rolling down a rocky hill. Many of the witnesses were farmers, said Judy Albin, a Weston Historical Society trustee. They were the ones who were up in the early morning milking the cows, she said. One woman in Massachusetts, near the Connecticut border, was on her farm when she saw the fireball streaking across the sky. She thought it was the moon. She said, where is the moon going? Then it disappeared behind a cloud. One farmer said his cattle were so terrified they jumped over a fence into a neighboring field, Albin said. Yet many had a pragmatic read on the rocks that fell from the sky. They didn't know what (the meteorite) was all about, Albin said. But they thought if it came from outer space, it could have gold or silver. So they gathered up the pieces and pulverized them. Unfortunately, there was no gold or silver to be found. Still, the residents who dug up the pieces of meteorite - some burrowed several feet into the ground - were an enterprising bunch, said Barbara Narendra, an archivist at the Peabody. The 28-pound piece of rock didn't make it to Yale until several years after the meteorite struck. It was sold for $130 in 1808 to a collector named George Gibbs, whose mineral collection eventually ended up with the university, Narendra said. Originally, she said, Gibbs offered $1 and the seller demanded $500. They compromised, and the rest is history. Falling to Earth To mark the 200th anniversary of the Weston meteorite's collision with Earth, the Weston and Easton historical societies, along with Yale Peabody Museum, are holding a series of commemorative events: * Time capsule, Friday, 6 a.m., Easton Public Library A fragment of the Weston meteorite will return to the area where it fell 200 years ago. The Weston and Easton historical societies will bury a time capsule of the history of scientific knowledge gained in the 200 years since the meteorite's impact. * Panel discussion, Friday, 7:30 p.m., Weston High School The Weston and Easton historical societies will sponsor a panel of meteor and planetary science experts in a discussion of the Scientific and Historical Significance of the Weston Meteorite: A Celebration of Two Centuries of Inquiry, Interpretation and Insight. Tickets are $15. For more information, call 227-1507. * Hands-on meteorite display, Saturday, 11 a.m. to 3 p.m., Yale Peabody Museum, New Haven. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Building Blocks of Life Formed on Mars (ALH84001)
http://www.ciw.edu/news/building_blocks_life_formed_mars Building blocks of life formed on Mars Carnegie Institution for Science December 11, 2007 Washington, DC - Organic compounds contain carbon and hydrogen and form the building blocks of all life on Earth. By analyzing organic material and minerals in the Martian meteorite Allan Hills 84001, scientists at the Carnegie Institution's Geophysical Laboratory have shown for the first time that building blocks of life formed on Mars early in its history. Previously, scientists have thought that organic material in ALH 84001 was brought to Mars by meteorite impacts or more speculatively originated from ancient Martian microbes. The Carnegie-led team made a comprehensive study of the ALH 84001 meteorite and compared the results with data from related rocks found on Svalbard, Norway. The Svalbard samples occur in volcanoes that erupted in a freezing Arctic climate about 1 million years ago - possibly mimicking conditions on early Mars. Organic material occurs within tiny spheres of carbonate minerals in both the Martian and Earth rocks, explained Andrew Steele, lead author of the study. We found that the organic material is closely associated with the iron oxide mineral magnetite, which is the key to understanding how these compounds formed. The organic material in the rocks from Svalbard formed when volcanoes erupted under freezing conditions. During cooling, magnetite acted as a catalyst to form organic compounds from fluids rich in carbon dioxide (CO2) and water (H2O). This event occurred under conditions where no forms of life are likely to exist. The similar association of carbonate, magnetite and organic material in the Martian meteorite ALH 84001 is very compelling and shows that the organic material did not originate from Martian life forms but formed directly from chemical reactions within the rock. This is the first study to show that Mars is capable of forming organic compounds at all. The organic material in the Allan Hills meteorite may have formed during two different events. The first, similar to the Svalbard samples, was during rapid cooling of fluids on Mars. A second event produced organic material from carbonate minerals during impact ejection of ALH 84001 from Mars. The results of this study show that volcanic activity in a freezing climate can produce organic compounds, remarked co-author Hans E.F. Amundsen from Earth and Planetary Exploration Services. This implies that building blocks of life can form on cold rocky planets throughout the Universe. Our finding sets the stage for the Mars Science Laboratory (MSL) mission in 2009, remarked Steele, who is a member of the Sample Analysis on Mars (SAM) instrument team onboard MSL. We now know that Mars can produce organic compounds. Part of the mission's goal is to identify organic compounds, their sources, and to detect molecules relevant to life. We know that they are there. We just have to find them. The research is published in Meteoritics Planetary Science http://meteoritics.org/index.htm For more information on the MSL mission and the SAM instrument see http://mars.jpl.nasa.gov/msl/ and http://ael.gsfc.nasa.gov/marsSAM.shtml _ This research was funded by NASA SRLIDA, ASTEP, NAI and ASTID programs; the Marshall Scholarship program; and the University of Oxford, Earth Sciences Department and was carried out in collaboration with the Arctic Mars Analog Svalbard Expedition (AMASE) project. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Sends EPOXI on Mission to Comet Hartley 2
Dec. 13, 2007 Grey Hautaluoma Headquarters, Washington 202-358-0668 [EMAIL PROTECTED] DC Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 [EMAIL PROTECTED] Nancy Neal Goddard Space Flight Center, Greenbelt, Md. 301-286-0039 [EMAIL PROTECTED] Lee Tune University of Maryland, College Park 301-405-4679 [EMAIL PROTECTED] RELEASE: 07-279 NASA SENDS SPACECRAFT ON MISSION TO COMET HARTLEY 2 WASHINGTON - NASA has approved the retargeting of the EPOXI mission for a flyby of comet Hartley 2 on Oct. 11, 2010. Hartley 2 was chosen as EPOXI's destination after the initial target, comet Boethin, could not be found. Scientists theorize comet Boethin may have broken up into pieces too small for detection. The EPOXI mission melds two compelling science investigations -- the Extrasolar Planet Observation and Characterization and the Deep Impact Extended Investigation. Both investigations will be performed using the Deep Impact spacecraft. In addition to investigating comet Hartley 2, the spacecraft will point the larger of its two telescopes at nearby exosolar planetary systems in late January 2008 to observe several previously discovered planetary systems outside our solar system. It will study the physical properties of giant planets and search for rings, moons and planets as small as three Earth masses. It also will look at Earth as though it were an exosolar planet to provide data that could become the standard for characterizing these types of planets. The search for exosolar planetary systems is one of the most intriguing explorations of our time, said Drake Deming, EPOXI deputy principal investigator at NASA's Goddard Space Flight Center, Greenbelt, Md. With EPOXI we have the potential to discover new worlds and even analyze the light they emit to perhaps discover what atmospheres they possess. The mission's closest approach to the small half-mile-wide comet will be about 620 miles. The spacecraft will employ the same suite of two science instruments the Deep Impact spacecraft used during its prime mission to guide an impactor into comet Tempel 1 in July 2005. If EPOXI's observations of Hartley 2 show it is similar to one of the other comets that have been observed, this new class of comets will be defined for the first time. If the comet displays different characteristics, it would deepen the mystery of cometary diversity. When comet Boethin could not be located, we went to our backup, which is every bit as interesting but about two years farther down the road, said Tom Duxbury, EPOXI project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Mission controllers at JPL began directing EPOXI towards Hartley 2 on Nov. 1. They commanded the spacecraft to perform a three-minute rocket burn that changed the spacecraft's velocity. EPOXI's new trajectory sets the stage for three Earth flybys, the first on Dec. 31, 2007. This places the spacecraft into an orbital holding pattern until time for the optimal encounter of comet Hartley 2 in 2010. Hartley 2 is scientifically just as interesting as comet Boethin because both have relatively small, active nuclei, said Michael A'Hearn, principal investigator for EPOXI at the University of Maryland, College Park. EPOXI's low mission cost of $40 million is achieved by taking advantage of the existing Deep Impact spacecraft. JPL manages EPOXI for NASA's Science Mission Directorate, Washington. The spacecraft was built for NASA by Ball Aerospace Technologies Corp., Boulder, Colo. For information about EPOXI, visit: http://www.nasa.gov/epoxi -end- __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Exploration Rover Update - December 14, 2007
http://marsrovers.jpl.nasa.gov/mission/status.html SPIRIT UPDATE: Spirit Scouts Home Plate for Safe Haven - sol 1390-1397, December 14, 2007: Spirit has arrived at the north edge of Home Plate. The rover will spend the next few Martian days, or sols, scouting the edge of Home Plate and acquiring images of the slopes to determine the best site for Winter Haven 3, where Spirit will try to survive another season of minimal sunlight. Once the team selects a site, Spirit will drive down the north-facing edge of Home Plate and maneuver into position to achieve the highest northerly tilt possible. Power levels are dropping rapidly, partly because the sun continues its retreat north on its way to winter solstice, and partly because the landscape tilts slightly southward near the rim. Drive sols are so precious and few, the team has been working long hours and weekends to make the most of the remaining sunlight. Sol-by-sol summary: In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities: Sol 1390 (Nov. 30, 2007): Spirit drove in search of Winter Haven 3 and acquired post-drive images with the navigation camera. Spirit acquired full-color images, using all 13 filters of the panoramic camera, of the low, sandy area nicknamed Tartarus. The rover surveyed Tartarus with the miniature thermal emission spectrometer and surveyed the horizon with the panoramic camera. Sol 1391: Spirit continued to drive in search of Winter Haven 3 and acquire post-drive images with the navigation camera. The rover assessed atmospheric opacity caused by suspended dust with the navigation camera. Spirit acquired a mosaic of images with the panoramic camera and monitored dust accumulation on the rover mast assembly. Sol 1392: Spirit drove in search of Winter Haven 3 and acquired a post-drive image mosaic and a rearward-looking image mosaic with the navigation camera. Sol 1393: Spirit continued to drive in search of Winter Haven 3. Spirit acquired a post-drive image mosaic and a rearward-looking image mosaic with the navigation camera. The rover also completed a survey of rock clasts and a systematic ground survey with the panoramic camera. Sol 1394: Spirit drove in search of Winter Haven 3 and acquired post-drive and rearward-looking image mosaics with the navigation camera. Spirit also acquired an image mosaic of Home Plate with the panoramic camera. Sol 1395: Spirit drove in search of Winter Haven 3 and acquired post-drive images with the navigation camera. Spirit acquired a mosaic of panoramic camera images of a target known as Hummock and a rearward-looking mosaic of navigation camera images. Sol 1396: Spirit continued driving in search of Winter Haven 3. The rover acquired post-drive and rearward-looking image mosaics with the navigation camera. Spirit completed a survey of rock clasts and a systematic ground survey with the panoramic camera. Sol 1397 (Dec. 8, 2007): Plans called for Spirit to continue driving in search of Winter Haven 3, acquire post-drive images with both the navigation and panoramic cameras, and conduct a systematic ground survey as well as acquire spot images of the sky with the panoramic camera. Odometry: As of sol 1397 (Dec. 8, 2007), Spirit's total odometry was 7495.15 meters (4.66 miles). __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images - December 10-14, 2007
MARS ODYSSEY THEMIS IMAGES December 10-14, 2007 o Dunes (Released 10 December 2007) http://themis.asu.edu/zoom-20071210a o Dao Vallis (Released 11 December 2007) http://themis.asu.edu/zoom-20071211a o Windstreaks (Released 12 December 2007) http://themis.asu.edu/zoom-20071212a o Hypansis Vallis (Released 13 December 2007) http://themis.asu.edu/zoom-20071213a o Argyre Dunes (Released 14 December 2007) http://themis.asu.edu/zoom-20071214a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Exploration Rovers Update - December 17, 2007
http://marsrovers.jpl.nasa.gov/mission/status.html SPIRIT UPDATE: Final Winter Haven Selection Near - sol 1398-1403, December 17, 2007: To make the most of waning sunlight during the approach of Martian winter, Spirit's handlers have returned to Mars time. This means their working hours coincide with the Martian day, as they did for the first three months after the rover landed on the red planet. Because a Martian day is about 40 minutes longer than an Earth day, Mars time can coincide with all hours of the day and night on Earth. The alarm might go off the same time one day, 40 minutes later the next day, an hour and 20 minutes later the next day, and so on. Spirit's solar power levels continue to drop, with solar array energies recently ranging from 293 watt-hours to 254 watt-hours, depending on the vehicle's orientation relative to the Sun. (One hundred watt-hours is the amount of energy needed to light a 100-watt bulb for one hour.) All members of the rover science team -- drivers, engineers, and scientists -- are evaluating data to select a place where the rover will attempt to survive another Martian winter, focusing on areas that will tilt the rover's solar panels to the north more than 25 degrees. They will select a final location from a narrowed list of choices based on proximity to the rover's current position and the characteristics of the terrain, with an eye for accessibility as well as continued exploration in the spring. Spirit reached the northern edge of Home Plate after driving 13.24 meters (43.44 feet) on Martian day, or sol, 1397 (Dec. 8, 2007). Three Martian days later, on sol 1400 (Dec. 11, 2007), Spirit finished collecting reconnaissance images of the northern exposure of the elevated plateau. During the past week, rover planners got a special visit from two Tuskegee Airmen, the first black pilots to serve in the U.S. military. The pilots shared stories about serving in World War II while learning about rover operations. Sol-by-sol summary: In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, and measuring atmospheric dust levels with the panoramic camera, Spirit completed the following activities: Sol 1398 (Dec. 9, 2007): Spirit drove 6.5 meters (21.3 feet) in a path nearly parallel to the northern edge of Home Plate. The rover acquired post-drive images with the hazard avoidance cameras and a mosaic of images with the navigation camera. Sol 1399: Spirit drove 7.19 meters (23.6 feet) toward a small promontory to acquire images of the slopes below. The rover acquired post-drive images with the hazard avoidance cameras and a mosaic of images with the navigation camera. The following morning, Spirit acquired a series of navigation camera images to complete a 360-degree view of the rover's location after completing the drive. Sol 1400: Spirit nudged 0.75 meter (2.5 feet) closer to the edge of Home Plate for a better view of what lay below. The rover acquired post-drive images with the hazard avoidance cameras and a mosaic of images with the navigation camera. Sol 1401: Spirit took a break from driving and acquired images with the panoramic camera before turning around to back down the steep slope where the rover will spend the winter. After turning, the rover's solar arrays blocked the view of the slope by cameras on the rover mast assembly. Following the maneuver, Spirit acquired two image mosaics with the panoramic camera. Sol 1402: Spirit acquired a pre-drive image of a pointy rock known as General B.O. Davis before backing up 2.5 meters (8.2 feet) and turning 180 degrees. The rover acquired post-drive images using the hazard avoidance cameras and a mosaic of images using the navigation camera. The following morning, Spirit monitored dust on the panoramic camera mast assembly and completed a systematic ground survey and a survey of rock clasts with the panoramic camera. Sol 1403 (Dec. 14, 2007): Plans called for Spirit to approach the edge of Home Plate backward and acquire post-drive images with the hazard avoidance cameras as well as an image mosaic with the panoramic camera. Odometry: As of sol 1402 (Dec. 13, 2007), Spirit's total odometry was 7523.31 meters (4.67 miles). OPPORTUNITY UPDATE: Opportunity Maneuvers Around Steeper Slopes in Victoria Crater - sol 1375-1381, Dec 17, 2007: Opportunity is now in the process of driving to the third band of light-colored rocks that circumvent Victoria Crater beneath the rim. Scientists had initially planned to have the rover head directly downhill to a rock target nicknamed Ronov, within the band known as Lyell. They selected an alternate rock exposure, dubbed Newell, when engineers determined that the original drive route would tilt the rover 25 degrees, somewhat higher than desired. The estimated tilt along the new route is a much
[meteorite-list] Astronauts to Comb International Space Station for Meteorite Strike
http://news.theage.com.au/astronauts-comb-iss-for-meteorite-strike/20071214-1h27.html Astronauts comb ISS for meteorite strike The Age (Australia) December 14, 2007 Two astronauts on the International Space Station will make a spacewalk next week to find out if a micro-meteorite strike damaged a critical part of the outpost's power system, officials say. The station is not in any danger and is still producing enough power to support the arrival of Russian cargo ship later this month, said station deputy program manager Kirk Shireman. NASA has now announced the space shuttle Atlantis will not take off until January 10 with Europe's Columbus science module on board. That flight, originally planned for last week, was postponed when sensors in the shuttle's fuel tank failed during two launch attempts. Shireman said the power problem would probably not affect plans to attach Columbus to the station next month. But flights of Japanese modules in February and April could be affected. Without repairs, we know we can't go too much farther, he said. Station commander Peggy Whitson and flight engineer Dan Tani are scheduled for a 6.5-hour spacewalk on Tuesday to inspect two joints needed to position the station's right-side solar panels toward the sun. The primary joint, which rotates the panels 360 degrees, was locked in place in October after spacewalking astronauts during the last shuttle mission discovered metal shards inside the mechanism. Additional inspections were planned during Atlantis' mission, but the work was shifted to the station crew's schedule after the launch was postponed. An additional problem with a second joint, which lets the panels pivot even while the primary joint is locked, surfaced on December 8. It makes power generation much more difficult, Shireman said. Because several independent pieces of equipment were simultaneously affected, engineers suspect a micro-meteorite strike may be to blame. They also theorised a piece of debris may have worked itself free and floated into an area that shorted out electrical components. Spare parts to fix the second joint are on board the station, though if the problem is with the device's cables a repair would have to wait until supplies arrive on the next cargo ship or aboard the shuttle, Shireman said. This (spacewalk) is a fact-finding mission, he said. It is hoped that something the crew sees can help us narrow down the problem. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Journal - December 17, 2007
http://dawn.jpl.nasa.gov/mission/journal_12_17_07.asp Dawn Journal Dr. Marc Rayman December 17, 2007 Dear Aficidawnados, Dawn is climbing away from the Sun on a blue-green pillar of xenon ions as it begins a new chapter in its mission. After the remarkably successful initial checkout phase, the project is now in the interplanetary cruise phase. When last we visited Dawn, it had superbly demonstrated that it was ready to fly the way it will for most of the mission. Although there will be many special activities during its journey to Vesta and from there to Ceres (and be sure to visit this site again to be among the best informed on your planet of what Dawn is doing), the probe will spend most of its time doing what it is doing today: patiently reshaping its orbit around the Sun with its amazingly efficient ion propulsion system. Without taking any more time than was needed for some high fives (and a few high sixes for the more mathematically avant-garde) following the flawless execution of the test of long-term thrusting, the team turned its attention to more checkout activities. Ion thruster #2 was the focus of tests on November 13 - 15, and the excellent results matched those of thrusters #1 and #3. (The identities and locations of the thrusters were revealed in a previous log before such information could be publicized by more sensational, vulgar sources.) November 19 was the first in-flight use of the spacecraft's main antenna. (In fact, that antenna was used in some of the thruster #2 tests, in which the spacecraft was oriented so the antenna cast a shadow on the thruster. This permitted operation at the highest throttle level without overheating while still relatively close to the Sun. We recommend even to official Dawn scorekeepers that that not count as the antenna's first use.) Because of the celestial geometry earlier in the mission, pointing the main antenna to Earth would have exposed sensitive components elsewhere on the craft to too much solar heating. All communications prior to the use of the main antenna relied on 1 of the 3 smaller antennas that do not emit as tight a radio beam. As the distance to the spacecraft increases, the smaller antennas will allow only very slow communications, while the main antenna, with a diameter of 1.52 meters (5 feet), will permit the return of many pictures and other scientific data even from distant Vesta and Ceres. Much of the rest of the initial checkout phase was dedicated to updating software on the spacecraft. Many units onboard, both in engineering subsystems and in science instruments, incorporate their own computers, but the command and data handling subsystem contains the master computers. One main computer runs operations aboard the ship, and another computer supports it (and has a few other responsibilities of its own). Each of these computers has an identical backup, able to take over should the primary unit experience problems. With a planned 8-year mission in the forbidding environment of deep space, Dawn may face challenges that require more than such backup hardware. So each main and each support computer holds both a primary and a backup copy of the software. If radiation or some other problem corrupts one version of the software, the system can detect that and resort to another. Engineers recognized well before launch that new software would need to be loaded during the initial checkout phase. As extensive as ground testing was, the team anticipated that the need for some updates would be identified once Dawn was operating in space. In addition, during the last few months before launch, when ongoing testing ferreted out bugs, only those changes that were essential for the beginning of the mission were made. Modifying complicated software is -- well, complicated; and seemingly simple changes can have unintended consequences. To allow thorough testing of the spacecraft's capability to complete the complex and critical steps after separating from its Delta rocket, as described on September 21, late prelaunch changes to the software were kept to a minimum, and an improved version was planned for November. Following the popular trend of giving software a snazzy name, the project denoted the latest suite flight software 7.0. We fully expect this to inspire new toys, movies, fashions, and even lifestyles (particularly among readers in the Pleiades), and Dawn's marketing department is standing by to work with you. On November 20, the new software for the support computers was radioed from Earth and installed separately on the primary and backup units in the command and data handling system. The software for each computer requires 67 files occupying about 135 kilobytes with a total of 22,800 lines written in the programming language C and in assembly code. The backup copies of the 7.0 software were transmitted to both computers on December 6. Each of these activities required great care, verifying that the computer memory remained
[meteorite-list] NASA's Dawn Spacecraft Begins Interplanetary Cruise Phase
http://www.jpl.nasa.gov/news/features.cfm?feature=1559 NASA's Dawn Spacecraft Begins Interplanetary Cruise Phase Jet Propulsion Laboratory December 18, 2007 NASA's Dawn spacecraft has successfully completed the initial checkout phase of the mission and begun its interplanetary cruise phase, which is highlighted by nearly continuous thrusting of its ion propulsion system. Dawn is on a 8-year, 3-billion mile journey to asteroid Vesta and dwarf planet Ceres. Media contact: DC Agle/JPL 818-393-9011 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - December 19, 2007
MARS RECONNAISSANCE ORBITER HIRISE IMAGES December 19, 2007 o Santa Claus Craters http://hirise.lpl.arizona.edu/PSP_006271_2210 o Chryse Planitia Surfaces http://hirise.lpl.arizona.edu/PSP_006268_1995 o Exposure of Basal Section of Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_006262_1080 o Cerberus Fossae and Surrounding Features http://hirise.lpl.arizona.edu/PSP_006234_1870 o Pang Boche Crater http://hirise.lpl.arizona.edu/PSP_005388_1975 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Chips Off an Old Lava Flow (Lunar Meteorite Kalahari 009)
http://www.psrd.hawaii.edu/Dec07/cryptomareSample.html Chips Off an Old Lava Flow Planetary Science Research Discoveries December 19, 2007 --- Lunar meteorite Kalahari 009 contains fragments of basalt about 4.35 billion years old, a record-breaking old age for mare basalt. Written by G. Jeffrey Taylor Hawai'i Institute of Geophysics and Planetology Photogeologic and remote sensing studies of the Moon show that many light-colored, smooth areas in the highlands contain craters surrounded by dark piles of excavated debris. The dark deposits resemble the dark basalts that make up the lunar maria. They contain the same diagnostic minerals (especially high-calcium pyroxene) and chemical compositions (high iron oxide) as do mare basalts. The deposits formed when vast amounts of material ejected during the formation of giant impact basins covered pre-existing lava plains. Since the smooth plains are older than the youngest impact basin (about 3.8 billion years old), the lavas must have erupted before formation of the visible maria. In fact, they were visible maria for a while eons ago, but were buried by ejecta when the basins formed. We have samples of these ancient mare basalts. They reside in breccias collected from the lunar highlands. Age dating indicates that the chips have ages of 3.9 billion years and older. The oldest dated mare basalt in the Apollo collection is 4.23 billion years. Now Kentaro Terada (Hiroshima University, Japan), Mahesh Anand (Open University, UK), Anna Sokol and Addi Bischoff (Institute for Planetology, Muenster, Germany), and Yuji Sano (The University of Tokyo, Japan) have determined the age of pieces of an ancient lava flow in a lunar meteorite, Kalahari 009, found in Botswana in 1999. The team dated this very low-titanium mare basalt by using an ion microprobe to measure the isotopic composition of lead and uranium in phosphate minerals. They found that the basalt fragments in the rock have an age of about 4.35 (plus or minus 0.15) billion years. This overlaps with the ages of chemically-distinct igneous rocks from the highlands, indicating that diverse magmas were being produced early in the history of the Moon. Reference: * Terada, K., Anand, M., Sokol, A. K., Bischoff, A., and Sano, Y. (2007) Cryptomare Magmatism 4.35 Billion Years Ago Recorded in Lunar Meteorite Kalahari 009. Nature, v. 450, p. 849-853. PSRDpresents: Chips Off an Old Lava Flow --Short Slide Summary http://www.psrd.hawaii.edu/Dec07/PSRD-cryptomareSample.ppt (with accompanying notes). Visible and Hidden Lava Plains From the moment Galileo peered at the Moon through his homemade telescope, he recognized two main areas on the Moon (see photograph): the rugged, light-colored highlands (which he named terra) and the smoother, darker areas (maria). Maria is the Latin word for sea, which Galileo figured them might be. We did not know for sure what they were until Apollo 11 astronauts retrieved samples from Mare Tranquillitatis. They are basalts--ancient lava flows that flooded low areas, many the interiors of large impact basins. Analyses of samples and remote sensing measurements show that the maria are dark because the lavas contain a lot more FeO (iron oxide) than do highland rocks. FeO inside a mineral such as pyroxene makes it darker. In addition, the mare basalts contain less plagioclase feldspar, a light-colored mineral. Hence, the maria are dark. They are smooth in part because they are so much younger than the highlands and so did not accumulate as many craters. However, they are also smoother because lava flows fill up low areas, tending to produce smooth plains. Many areas in the highlands are smooth plains, but they are light colored, hence low in FeO. Remote sensing shows that they are not composed of mare basalts. However, many light plains deposits are decorated with impact craters surrounded by dark piles of ejecta, nicknamed dark-haloed craters. These curious features were debated for years. Finally, Pete Schultz (now at Brown University) and Paul Spudis (now at the Lunar and Planetary Institute, Houston) assembled all the available evidence to make a good case that the dark-haloed craters formed when mare basalt lava flows were covered with ejecta from large impact craters and basins, and then small craters punctured through the ejecta to toss out mare basalt. Detailed studies during the 1980s by B. Ray Hawke and Jeff Bell (University of Hawaii), and investigators elsewhere, provided further evidence that many light plains in the highlands are underlain by dark basaltic rock. In 1992, Jim Head (Brown University) and Lionel Wilson (Lancaster University, UK) named these widespread deposits cryptomaria, meaning hidden maria. Clementine images of dark-haloed craters on the Moon LEFT: Seventeen dark-haloed craters are indicated by numbers on this image mosaic from Clementine 750 nm remote sensing
[meteorite-list] Catastrophic Impacts Made Life Flourish
http://www.msnbc.msn.com/id/22298683/ Catastrophic impacts made life flourish Meteorites linked to an explosion in biodiversity millions of years ago By Dave Mosher MSNBC December 17, 2007 Space rocks are blamed for a lot of rough times on Earth, from the die-off of most marine animals some 250 million years ago to the disappearance of the dinosaurs 65 million years in the past. A new theory, however, suggests that catastrophic meteorite impacts are linked to an explosion in biodiversity about 470 million years ago, during the Ordovician Period. Within a few million years, the number of trilobite species and scores of other creatures on Earth jumped at least three to four times. Birger Schmitz, a geologist at the University of Lund in Sweden who worked for more than 10 years to help gather evidence backing up the claim, is the first to admit that his group's findings are hard to swallow. It seems completely at odds with anyone's expectations, Schmitz said, but you have to remember, for example, that it was at first difficult for many scientists to accept asteroid explanations for the disappearance of the dinosaurs. Schmitz and his colleagues detail their findings in the Dec. 16 advance issue of the journal Nature Geoscience. Smackdown Just before the jolt to Ordovician life, Schmitz said two massive bodies in the Asteroid Belt slammed into one another, littering the solar system with rocks the size of Manhattan island and ranging down to microscopic bits of dust. Even today, more than 20 percent of the meteorites we see came from this breakup event, Schmitz said. That makes the L-chondrite meteorites, as they're known, the most common kind to rain down on Earth. Such extraterrestrial rocks contain a unique form of radioactive chromium, so Schmitz and his team were able to figure out precisely when, how much and how often the cosmic debris slammed into Earth. We saw a sudden jump in meteorite material around the time of increased biodiversity, Schmitz said - greater than 100 times more material, in fact. That's a major event, and an incredible coincidence that I don't think we should ignore, he told LiveScience.com. Schmitz cautioned that while the two events line up in an uncanny way, there is still a lot of work left to do to connect the increased meteorite impacts to inflating biodiversity. It took us about 15 years to accumulate data for this finding, and it's something that isn't just a computer model or simulation. It's real, tactile evidence, he said of the work, which included slowly acid-dissolving almost a ton of rock collected from around the world to sift out bits of chromium. The scientists compared their meteorite record to layers of fossilized plants and animals, determining that the cosmic smashup happened shortly before the biodiversity boost. I expect that it will take us another 15 years of playing in the dirt to get there, to find Ordovician impact craters and beds associated with this breakup, he said. Pushing their luck Schmitz isn't certain exactly how pummeling the planet with rocks could cause life to thrive, but he thinks it has something to do with creating new nooks and crannies for life to adapt to in its new environment. Before the breakup you had primitive animals adapted to rough conditions, so you could say they were prepared for the storm, Schmitz said. Schmitz also explained that evolution is very much give-and-take, as radiating into new species requires a figurative kick in the shins. If you push an ecosystem too hard, you'll destroy it, he said. But for the organisms living on Earth at the time, [the environment] pushed them to adapt and fill new niches. It's like at the university: I tell my students all the time that if we don't push you, you don't evolve. Whether or not the cosmic smashup ultimately caused life on Earth to thrive 470 million years ago, the connection between events in space and life on Earth is intriguing, Schmitz said. There's much more to be learned how the history of Earth and its life is related to the universe, he said. We're only in the beginning of exploring that connection. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Saturn's Rings May be Old Timers
http://www.jpl.nasa.gov/news/news.cfm?release=2007-149 Saturn's Rings May be Old Timers Jet Propulsion Laboratory December 12, 2007 SAN FRANCISCO, Calif. - New observations by NASA's Cassini spacecraft indicate the rings of Saturn, once thought to have formed during the age of the dinosaurs, instead may have been created roughly 4.5 billion years ago, when the solar system was still under construction. Larry Esposito, principal investigator for Cassini's Ultraviolet Imaging Spectrograph at the University of Colorado, Boulder, said data from NASA's Voyager spacecraft in the 1970s, and later from NASA's Hubble Space Telescope, led scientists to believe Saturn's rings were relatively youthful and likely created by a comet that shattered a large moon, perhaps 100 million years ago. But ring features seen by instruments on Cassini -- which arrived at Saturn in 2004 -- indicate the rings were not formed by a single cataclysmic event. The ages of the different rings appear to vary significantly, and the ring material is continually being recycled, Esposito said. The evidence is consistent with the picture that Saturn has had rings all through its history, said Esposito of the University of Colorado's Laboratory for Atmospheric and Space Physics. We see extensive, rapid recycling of ring material, in which moons are continually shattered into ring particles, which then gather together and re-form moons. Esposito and colleague Miodrag Sremcevic, also with the University of Colorado, are presenting these findings today in a news briefing at the meeting of the American Geophysical Union in San Francisco. We have discovered that the rings probably were not created just yesterday in cosmic time, and in this scenario, it is not just luck that we are seeing planetary rings now, said Esposito. They probably were always around but continually changing, and they will be around for many billions of years. Scientists had previously believed rings as old as Saturn itself should be darker due to ongoing pollution by the infall of meteoric dust, leaving telltale spectral signatures, Esposito said. But the new Cassini observations indicate the churning mass of ice and rock within Saturn's gigantic ring system is likely much larger than previously estimated. This helps explain why the rings overall appear relatively bright to ground-based telescopes and spacecraft. The more mass there is in the rings, the more raw material there is for recycling, which essentially spreads this cosmic pollution around, he said. If this pollution is being shared by a much larger volume of ring material, it becomes diluted and helps explain why the rings appear brighter and more pristine than we expected. Esposito, who discovered Saturn's faint F ring in 1979 using data from NASA's Pioneer 11 spacecraft, said a paper by him and his colleagues appearing in an upcoming issue of the journal Icarus supports the theory that Saturn's ring material is being continually recycled. Observing the flickering of starlight passing through the rings in a process known as stellar occultation, the researchers discovered 13 objects in the F ring ranging in size from 27 meters to 10 kilometers (30 yards to six miles) across. Since most of the objects were translucent -- indicating at least some starlight was passing through them -- the researchers concluded they probably are temporary clumps of icy boulders that are continually collecting and disbanding due to the competing processes of shattering and coming together again. The team tagged the clumpy moonlets with cat names like Mittens and Fluffy because they appear to come and go unexpectedly over time and have multiple lives, said Esposito. Esposito stressed that Saturn's rings of the future won't be the same rings we see today, likening them to great cities around the world like San Francisco, Berlin or Beijing. While the cities themselves will go on for centuries or millennia, the faces of people on the streets will always be changing due to continual birth and aging of new citizens. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington, D.C. For more information about the Cassini-Huygens mission, visit: http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini . To listen to a podcast of Esposito and view a short video animation of objects in Saturn's F ring shattering and re-forming, visit: http://www.colorado.edu/news/reports/space/. Media Contact: Carolina Martinez 818-354-9382 Jet Propulsion Laboratory, Pasadena, Calif. [EMAIL PROTECTED] Jim Scott 303-492-3114 University of Colorado, Boulder [EMAIL PROTECTED] 2007-149 __
Re: [meteorite-list] Asteroid may be set to slam Mars in Jan.
There is a NASA press release coming out on this today. We'll also post some graphics on the NEO website. Stay tuned. Ron Baalke __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images: December 17-21, 2007
MARS ODYSSEY THEMIS IMAGES December 17-21, 2007 o Liu Hsin Crater (Released 17 December 2007) http://themis.asu.edu/zoom-20071217a o Hydraotes Chaos (Released 18 December 2007) http://themis.asu.edu/zoom-20071218a o Large Landslide (Released 19 December 2007) http://themis.asu.edu/zoom-20071219a o Dunes (Released 21 December 2007) http://themis.asu.edu/zoom-20071221a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Freshly Painted Arecibo Observatory Returns To Work, Spies Asteroid 3200 Phaethon
http://www.news.cornell.edu/stories/Dec07/Arecibo.phaethon.html Chronicle Online e-News Freshly painted Arecibo Observatory returns to work, spies object associated with meteor showers http://www.news.cornell.edu/stories/Dec07/Arecibo.phaethon.html Dec. 21, 2007 By Lauren Gold [EMAIL PROTECTED] After receiving its first fresh, full coat of paint in more than 40 years, Arecibo Observatory made its first observation in more than six months at 6:36 a.m., Saturday, Dec. 8. The giant paint job was critical for ensuring the observatory's safety and structural integrity. The telescope focused on the asteroid 3200 Phaethon, which travels closer to the sun than any other numbered asteroid -- about twice as close to the sun as the planet Mercury. Phaethon is the source of the Geminid meteor shower, which causes streams of shooting stars every December. Jean-Luc Margot, Cornell assistant professor of astronomy, and Jon Giorgini of the NASA Jet Propulsion Laboratory (JPL), Pasadena, Calif., are studying Phaethon and other asteroids that have trajectories strongly affected by sunlight, sun shape and general relativity effects. Mike Nolan, an Arecibo staff scientist, conducted the Dec. 8 observation; Lance Benner of JPL leads the radar investigation of Phaethon. Asteroid orbits are influenced by the absorption and re-emission of solar energy -- or the so-called Yarkovsky effect. These changes to the asteroidal motion will be quantified with the Arecibo radar measurements to understand the properties of near-Earth asteroids. This is one of dozens of projects now under way at the observatory. The six-month painting project -- the first time the Arecibo platform and focal-point structure has received a thorough painting -- ended in November. Since then a skeletal crew of observatory staff worked around-the-clock to bring the 1,000-foot radio telescope and the planetary radar back to astronomical life. Now the observatory is fully functional, with all motion, electronic, transmitting and receiving, and computing systems operating. It is ready to return to the task of carrying out the scientific observations for the many thousands of hours of approved research programs that will keep the telescope very busy for the next several years, said Robert Brown, director of the National Astronomy and Ionosphere Center, a national research center operated by Cornell under a cooperative agreement with the National Science Foundation. -- __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] The United Nations Declares 2009 the International Year of Astronomy
IAU0702: FOR IMMEDIATE RELEASE http://www.iau.org/iau0702.486.0.html The United Nations declares 2009 the International Year of Astronomy 20-December-2007, Paris: Early this morning (CET) the United Nations (UN) 62nd General Assembly proclaimed 2009 the International Year of Astronomy. The Resolution was submitted by Italy, Galileo Galilei's home country. The International Year of Astronomy 2009 is an initiative of the International Astronomical Union and UNESCO. The International Year of Astronomy 2009 (IYA2009) celebrates the first astronomical use of the telescope by Galileo - a momentous event that initiated 400 years of astronomical discoveries and triggered a scientific revolution which profoundly affected our worldview. Now telescopes on the ground and in space explore the Universe, 24 hours a day, across all wavelengths of light. The President of the International Astronomical Union (IAU) Catherine Cesarsky says: The International Year of Astronomy 2009 gives all nations a chance to participate in this ongoing exciting scientific and technological revolution. The IYA2009 will highlight global cooperation for peaceful purposes - the search for our cosmic origin and our common heritage which connects all citizens of planet Earth. For several millennia, astronomers have worked together across all boundaries including geographic, gender, age, culture and race, in line with the principles of the UN Charter. In that sense, astronomy is a classic example of how science can contribute towards furthering international cooperation. At the IAU General Assembly on 23 July 2003 in Sydney (Australia), the IAU unanimously approved a resolution in favour of the proclamation of 2009 as the International Year of Astronomy. Based on Italy's initiative, UNESCO's General Conference at its 33rd session recommended that the UN General Assembly adopt a resolution to declare 2009 the International Year of Astronomy. On 20 December 2007 the International Year of Astronomy 2009 was proclaimed by the United Nations 62nd General Assembly. The UN has designated the United Nations Educational, Scientific and Cultural Organization (UNESCO) as the lead agency for the IYA2009. The IAU will function as the facilitating body for IYA2009. The IYA2009 is, first and foremost, an activity for the citizens of planet Earth. It aims to convey the excitement of personal discovery, the pleasure of sharing fundamental knowledge about the Universe and our place in it, and the merits of the scientific method. Astronomy is an invaluable source of inspiration for humankind throughout all nations. So far 99 nations and 14 organisations have signed up to participate in the IYA2009 - an unprecedented network of committed communicators and educators in astronomy. For more information on the International Year of Astronomy 2009 please visit the website at http://www.astronomy2009.org/ # # # Notes for editors The vision of the IYA2009 is to help the citizens of the world rediscover their place in the Universe through the day and night time sky - and thereby engage a personal sense of wonder and discovery. All humans should realize the impact of astronomy and basic sciences on our daily lives, and understand better how scientific knowledge can contribute to a more equitable and peaceful society. The aim of the IYA2009 is to stimulate worldwide interest, especially among young people, in astronomy and science under the central theme The Universe, Yours to Discover. IYA2009 events and activities will promote a greater appreciation of the inspirational aspects of astronomy that embody an invaluable shared resource for all nations. The IYA2009 activities will take place at the global and regional levels, and especially at the national and local levels. National Nodes in each country have been formed to prepare activities for 2009. These Nodes establish collaborations between professional and amateur astronomers, science centres, educators and science communicators in preparing activities for 2009. The IAU is the international astronomical organisation that brings together almost 10,000 distinguished astronomers from all nations of the world. Its mission is to promote and safeguard the science of astronomy in all its aspects through international cooperation. The IAU also serves as the internationally recognized authority for assigning designations to celestial bodies and surface features on them. Founded in 1919, the IAU is the world's largest professional body for astronomers. The United Nations 62nd General Assembly IYA2009 Resolution text (62/200): International Year of Astronomy, 2009 The General Assembly, Recalling its resolution 61/185 of 20 December 2006 on the proclamation of international years, Aware that astronomy is one of the oldest basic sciences and that it has contributed and still contributes fundamentally to the evolution of other sciences and applications in a wide range of fields, Recognizing
[meteorite-list] Mars Rovers Find New Evidence of 'Hapitable Niche'; Perilous 3rd Winter Approaches
http://www.news.cornell.edu/stories/Dec07/Rover.update.html Chronicle Online e-News Mars rovers find new evidence of 'habitable niche'; perilous third winter approaches Dec. 21, 2007 By Lauren Gold [EMAIL PROTECTED] Inch by power-conserving inch, drivers on Earth have moved the Mars rover Spirit to a spot where it has its best chance at surviving a third Martian winter -- and where it will celebrate its fourth anniversary (in Earth years) since bouncing down on Mars for a projected 90-day mission in January 2004. Meanwhile, researchers are considering the implications of what Cornell's Steve Squyres, principal investigator for NASA's Mars Exploration Rover mission, calls one of the most significant mission discoveries to date: silica-rich deposits uncovered in May by Spirit's lame front wheel that provide new evidence for a once-habitable environment in Gusev Crater. Squyres and colleagues reported the silica deposits at the annual meeting of the American Geophysical Union in early December in San Francisco. On the other side of Mars, Spirit's still-healthy twin Opportunity is creeping slowly down the inside of Victoria Crater, where layers of exposed rock are confirming findings made at the much smaller Eagle and Endurance craters -- and where deeper layers could offer new insight into the planet's history. Spirit, which has been driving backward since its right front wheel stopped turning in March 2006, was exploring near a plateau in the Gusev Crater known as Home Plate when scientists noticed that upturned soil in the wake of its dragging wheel appeared unusually bright. Measurements by the rover's alpha particle X-ray spectrometer and mini-thermal emission spectrometer showed the soil to be about 90 percent amorphous silica -- a substance associated with life-supporting environments on Earth. This is one of the most powerful pieces of evidence for formerly habitable conditions that we have found, said Squyres, Cornell's Goldwin Smith Professor of Planetary Science, in a Dec. 11 interview with the BBC. On Earth, silica deposits are found at hot springs, where hot water dissolves silica in rock below the surface, then rises and cools, causing the silica to precipitate out near the surface; and at fumaroles, where hot acidic water or vapors seep through rock, dissolving away other elements but leaving silica behind. Either place on Earth is teeming with microbial life, said Squyres. So this is, either way, a representation of what in the past was a local habitable environment -- a little habitable niche on the surface of Mars. The discovery was reminiscent of Spirit's journey to winter safety last year, when it uncovered (and briefly got mired in) patches of bright soil that contained high levels of sulfur -- another possible indicator of past hydrothermal activity. Unlike last year, though, Spirit enters this Martian winter handicapped by dusty solar panels -- the result of giant dust storms in June and July. So the rover's power levels, which currently range between approximately 290 and 250 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour; full power for the rovers is 800-900 watt-hours) -- could drop to dangerous levels in the dwindling winter sunlight. Spirit's perch is currently at a 15-degree tilt on the north-facing slope of the Home Plate plateau, said Jim Bell, Cornell associate professor of astronomy and leader of the mission's Pancam color camera team. As the sun moves lower in the Martian sky, drivers will nudge the rover to a steeper angle. The fact that we've gotten to a good tilt, and we're going to get to a better tilt, is a good sign, said Bell. Still, he added, any work the rover does over the winter -- collecting Pancam images of its surroundings, for example -- will be strictly low-exertion. Most of 2008 is going to be a quiet time for Spirit, he said. It's really about survival. -- __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Recently Discovered Asteroid Could Hit Mars in January (2007 WD5)
http://neo.jpl.nasa.gov/news/news151.html Recently Discovered Asteroid Could Hit Mars in January Steve Chesley and Paul Chodas NASA/JPL Near-Earth Object Program Office December 21, 2007 A recently discovered asteroid which passed close to the Earth in November, is now headed towards a very close passage by Mars in late January, and there is a small chance that it could hit that planet. The probability of a collision is only 1 chance in 75, but scientists are excited about the possibility. If it happens, the impact would occur on January 30, 2008 at around 10:55 UT (2:55 a.m. PST). [Graphic] The current position of asteroid 2007 WD5, with its orbit shown in blue. The asteroid's orbit stretches from just outside the Earth's orbit at its closest point to the Sun, to the outer reaches of the asteroid belt at its farthest. Uncertainty region at closest approach to Mars [Graphic] Uncertainty Region for 2007 WD5 at encounter with Mars, shown as white dots. The thin white line is the orbit of Mars. The blue line traces the motion of the center of the uncertainty region, which is the most likely position of the asteroid. In the likely event that the asteroid misses Mars, it could come back to the vicinity of the Earth years or decades later, but our routine hazard monitoring shows that there is no threat of an impact with the Earth. [Animation] Animation showing the motion of the uncertainty region of 2007 WD5 as it approaches Mars.The thin white line is the orbit of Mars. The blue line traces the motion of the center of the uncertainty region, which is the most likely position of the asteroid. Designated 2007 WD5, the asteroid was discovered on Nov. 20, 2007 by the NASA-funded Catalina Sky Survey using a 1.5m telescope on Mt. Lemmon, near Tucson. The object had already passed within 7.5 million km (5 million miles) of the Earth on Nov. 1, before it was discovered. Based on its magnitude, we estimate the asteroid to be about 50 meters (160 feet) across. As the accompanying diagram shows, it has already reached the halfway point between Earth and Mars. When it closes in on Mars, it will approach from the day side, and would then be very difficult to observe from any of the spacecraft on or around Mars. Our current best estimate predicts the asteroid will miss Mars by 50,000 km, but the miss distance is highly uncertain because the asteroid's path is not known with sufficient accuracy. The uncertainty region during the Mars encounter currently extends over a million kilometers (700,000 miles) along a very slender ellipsoid only 1200 km (700 miles) wide, but the ellipsoid does intersect Mars. The zone of potential impact on the surface of Mars is approximately 800 km wide, and sweeps across the Martian equator from southwest to northeast, crossing the equator at roughly 30 deg W longitude. The MER Opportunity rover is close to the southern edge of this possible impact zone but clearly outside it. The asteroid is becoming increasingly difficult to observe, since it is receding from the Earth and the waxing Moon is approaching the same part of the sky. But it should become observable again early in January. These new measurements will lead to a significant improvement in the orbit accuracy, and we will then be able to refine the probability that the asteroid might collide with Mars. If the asteroid is indeed on a collision course, it would hit Mars with a velocity of about 13.5 km/s (8.4 miles per second), and would produce an explosion equivalent to about 3 MT of TNT. We can only speculate as to the effects of such an impact, but it would be reasonable to expect a crater nearly a kilometer across and a significant amount of dust lifted into the atmosphere. An impact would not be unprecedented: 21 fragments of Comet Shoemaker-Levy 9 impacted Jupiter in July, 1994. Those impacts were predicted with near certainty almost a year before the impact. But, with a 1-in-75 chance, this asteroid's possible impact with Mars is far from certain. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Astronomers Monitor Asteroid to Pass Near Mars
Grey Hautaluoma Headquarters, Washington 202-358-0668 [EMAIL PROTECTED] D.C. Agle Jet Propulsion Laboratory, Pasadena, Calif. 818-393-9011 [EMAIL PROTECTED] Dec. 21, 2007 RELEASE : 07-284 Astronomers Monitor Asteroid to Pass Near Mars WASHINGTON - Astronomers funded by NASA are monitoring the trajectory of an asteroid estimated to be 164-feet wide that is expected to cross Mars' orbital path early next year. Observations provided by the astronomers and analyzed by NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif., indicate the object may pass within 30,000 miles of Mars at about 6 a.m. EST on Jan. 30, 2008. Right now asteroid 2007 WD5 is about half-way between the Earth and Mars and closing the distance at a speed of about 27,900 miles per hour, said Don Yeomans, manager of the Near Earth Object Office at JPL. Over the next five weeks, we hope to gather more information from observatories so we can further refine the asteroid's trajectory. NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called Spaceguard, plots the orbits of these objects to determine if any could be potentially hazardous to our planet. Asteroid 2007 WD5 was first discovered on Nov. 20, 2007, by the NASA-funded Catalina Sky Survey and put on a watch list because its orbit passes near the Earth. Further observations from both the NASA-funded Spacewatch at Kitt Peak, Ariz., and the Magdalena Ridge Observatory in New Mexico gave scientists enough data to determine that the asteroid was not a danger to Earth, but could potentially impact Mars. This makes it a member of an interesting class of small objects that are both Near Earth Objects and Mars crossers. Because of current uncertainties about the asteroid's exact orbit, there is a 1-in-75 chance of 2007 WD5 impacting Mars. If this unlikely event were to occur, it would be somewhere within a broad swath across the planet north of where the Opportunity rover is. We estimate such impacts occur on Mars every thousand years or so, said Steve Chesley, a scientist at JPL. If 2007 WD5 were to thump Mars on Jan. 30, we calculate it would hit at about 30,000 miles per hour and might create a crater more than half-a-mile wide. The Mars Rover Opportunity is currently exploring a crater approximately this size. Such a collision could release about three megatons of energy. Scientists believe an event of comparable magnitude occurred here on Earth in 1908 in Tunguska, Siberia, but no crater was created. The object was disintegrated by Earth's thicker atmosphere before it hit the ground, although the air blast devastated a large area of unpopulated forest. NASA and its partners will continue to track asteroid 2007 WD5. For more information, visit: http://neo.jpl.nasa.gov/ - end - __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Catalina Sky Survey Discovers Space Rock That Could Hit Mars
http://uanews.org/node/17415 FROM: Lori Stiles (520-626-4402 [EMAIL PROTECTED]) CATALINA SKY SURVEY DISCOVERS SPACE ROCK THAT COULD HIT MARS UA-based HiRISE team would have a ring-side seat - Sent December 21, 2007 An asteroid discovered by The University of Arizona's Catalina Sky Survey has a one-in-75 chance of hitting Mars Jan. 30, scientists tracking it say. Catalina Sky Survey team member Andrea Boattini discovered the asteroid, designated 2007 WD5, with UA's Mount Lemmon 60-inch telescope in the Santa Catalina Mountains north of Tucson on Nov. 20. At the time, the asteroid was at 20th magnitude brightness, which is about 400,000 times fainter than the faintest object most people can see with their naked eye on a dark night, survey team member Ed Beshore said. The asteroid is now 16 times dimmer than it was when it was discovered, he added. Astronomers monitoring the trajectory of the asteroid estimate it to be 164-feet wide. Observations provided by the astronomers and analyzed by NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif., indicate the object may pass within 30,000 miles of Mars at about 6 a.m. EST on Jan. 30, 2008. The Mars-approaching asteroid is about the size of the object that blasted out Meteor Crater, Ariz., 50,000 years ago. The object that created Meteor Crater is believed to be a metallic asteroid - more like a ball bearing that a rock, Beshore said. The newly found Mars-approaching asteroid is probably a stony asteroid, as are most asteroids, Beshore said. Scientists calculate it is traveling at eight miles a second, or 15 times faster than a rifle bullet, he added. Asteroid 2007 WD5 is also being compared to the object that exploded over Tunguska, Siberia, with the energy of a three megaton bomb in 1908. The Tunguska object is believed to be the midair explosion of a cometary fragment, Beshore said. In the unlikely event that 2007 WD5 does hit Mars, it would hit somewhere within a broad swath across the planet north of where the Opportunity rover is, according to NASA. We estimate such impacts occur on Mars every thousand years or so, Steve Chesley, an astronomer with the Near Earth Object Program at NASA's Jet Propulsion Laboratory, said in a NASA news release. If 2007 WD5 were to thump Mars on Jan. 30, we calculate it would hit at about 30,000 miles per hour and might create a crater more than a half-a-mile wide. The Mars Reconnaissance Orbiter, which is mapping the planet, would have a front-row seat, Chesley added. The orbiter's science payload includes the High Resolution Imaging Experiment, or HiRISE, which operates the most powerful camera ever to orbit another planet. If the asteroid hits Mars we'll get a great look at the crater within a few days of impact, HiRISE principal investigator Alfred S. McEwen of UA's Lunar and Planetary Laboratory said. HiRISE images of recent Martian impact craters can be found on the HiRISE Website, http://hirise.lpl.arizona.edu The Catalina Sky Survey broke all records for discoveries of near-Earth objects, or NEOs, for any NEO survey this year. The survey found 450 NEOs in 2007, although that number will rise slightly when the final count is in, Beshore said. That tops its ealier record 400 NEO discoveries in 2006 and record 310 NEO discoveries in 2005. The team's growing success in making NEO discoveries reflects that the survey continues to improve its technique and technologies, said the Lunar and Planetary Laboratory's Steve Larson, Catalina Sky Survey director. The Catalina Sky Survey, known as the CSS, is conducted in the northern hemisphere by the Mount Lemmon Survey north of Tucson, Ariz., and in the southern hemisphere by the Siding Spring Survey near Coonabarabran, New South Wales, Australia. CSS is one of four surveys funded by NASA to carry out a U.S. congressional mandate to find and catalog at least 90 percent of all near-Earth objects, larger than one kilometer across (six-tenths mile) by the end of 2008. The impact of a kilometer-diameter asteroid would have global consequences to civilization as we know it, Larson said. If an object even a third as large hit Earth, it would explode with 24 times the energy of the world's largest thermonuclear bomb explosion, a 58 megaton Soviet bomb exploded in 1961. The technology to detect and track these objects has been available for only a decade, and although impacts of these large NEOs are rare, we can for the first time quantify any potential danger as the first step in possibly mitigating a disaster, he said. CONTACTS: Steve Larson (520-621-4973 office; 520-490-4053 cell; [EMAIL PROTECTED]) Ed Beshore (520-621-4900 office; 520-396-9186 cell; [EMAIL PROTECTED]) WEB LINKS: Catalina Sky Survey - http://www.lpl.arizona.edu/css NASA NEO Program - http://neo.jpl.nasa.gov/news/news151.html HiRISE - http://hirise.lpl.arizona.edu __ http://www.meteoritecentral.com Meteorite-list
[meteorite-list] Mars Impact Probability Increases to 4 Percent (Asteroid 2007 WD5)
http://neo.jpl.nasa.gov/news/news153.html Mars Impact Probability Increases to 4 Percent Don Yeomans, Paul Chodas and Steve Chesley NASA/JPL Near-Earth Object Program Office December 28, 2007 The impact probability for a collision of asteroid 2007 WD5 with Mars on January 30 has increased from 1.3% to 3.9%. Pre-discovery observations of asteroid 2007 WD5, taken on November 8, 2007 have allowed its orbit to be refined and the uncertainties for the late January Mars encounter have been improved. The impact probability resulting from the recent orbit refinement has increased to a surprising 3.9% (about 1 in 25 odds). The uncertainty region during the Mars encounter now extends over 400,000 km along a very narrow ellipsoid that is only 600 km wide. Since the uncertainty region intersects Mars itself, a Mars impact is still possible. However, the most likely scenario is that additional observations of the asteroid will allow the uncertainty region to shrink so that a Mars impact is ruled out. In the unlikely event of an impact, the time would be 2008 January 30 at 10:56 UT (2:56 a.m. PST) with an uncertainty of a few minutes. The pre-discovery observations were located by Andy Puckett, a recent Ph.D. from the University of Chicago who has since moved to the University of Alaska Anchorage. Dr. Puckett located the observations in the archive of the Sloan Digital Sky Survey II, which contains extensive repeat coverage of 300 square degrees along the sky's celestial equator. The observations were taken using a 2.5 meter aperture telescope at the Apache Point Observatory near Cloudcroft, New Mexico. For the recent orbit refinement, these pre-discovery observations on November 8 were added to the existing observations provided by the Catalina Sky Survey and Spacewatch observatories (both near Tucson AZ) as well as New Mexico Tech's Magdalena Ridge Observatory. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] International Conference: 100 Years Since Tunguska Phenomenon - Past, Present and Future
http://tunguska.sai.msu.ru/ International Conference 100 years since Tunguska phenomenon: Past, present and future June 26-28, 2008. Moscow, Russia The Conference is organized by * Russian Academy of Sciences - Institute for Dynamics of Geospheres * Lomonosov Moscow State University - Sternberg Astronomical Institute, Institute of Mechanics * Meteorite Committee of Russian Academy of Sciences Purposes The Conference is devoted to the 100-year anniversary of the Tunguska phenomenon. The purpose of the conference is to integrate the efforts of inter-disciplinary experts in understanding the Tunguska event and similar impact phenomena. Problems for discussion 100 years since the Tunguska event 1. Mathematical modeling of trajectory, dynamics and explosion of Tunguska cosmic object 2. Search of material of Tunguska object 2.1. Analysis of particles in soil, tree trunks and resin 2.2. Separation of cosmic dust input and aerosol sources from the background 3. Effects of global scale 3.1. Light nights 3.2. Ionosphere perturbations 3.3. Search of anomalies in Arctic and Antarctic 4. Regional and local effects 4.1. Analysis of eyewitness reports 4.2. Study of tree fall and state of forest after the Tunguska event 4.3. Investigation of magnetic properties and thermoluminescense of soil and rocks at the site 5. Ecological consequences of the Tunguska event. Genetic aspect of the problem 6. Historical, ethnographic and sociological issues connected with the Tunguska catastrophe Exploration of asteroids and comets 1. Significance of exploration of asteroids and comets for understanding of evolution of the Solar System and exoplanetary systems 2. Problems of origin and evolution of comets and asteroids 3. Studies of minor bodies of the Solar System (asteroids, comets, meteoroids) by means of spacecrafts Hazards due to comets and asteroids 1. The role of the Tunguska event in the problem of asteroidal and cometary hazards 2. Investigation of impact craters on the Earth and other bodies of the Solar System 3. Means of mitigation of asteroidal and cometary hazards __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - December 26, 2007
MARS RECONNAISSANCE ORBITER HIRISE IMAGES December 26, 2007 o Repeated Erosion and Deposition in the South Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_005788_1035 o Crater on the South Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_005748_1075 o Distorted Layers in the South Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_005418_1075 o Impact Crater on the South Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_005392_0995 o South Polar Layered Deposits http://hirise.lpl.arizona.edu/PSP_004965_0980 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images: December 24-28, 2007
MARS ODYSSEY THEMIS IMAGES December 24-28, 2007 o Lava Flows (Released 24 December 2007) http://themis.asu.edu/zoom-20071224a o Polar Outliers (Released 25 December 2007) http://themis.asu.edu/zoom-20071225a o Landslides (Released 26 December 2007) http://themis.asu.edu/zoom-20071226a o Dust Devil Tracks (Released 27 December 2007) http://themis.asu.edu/zoom-20071227a o Canyon Ridges (Released 28 December 2007) http://themis.asu.edu/zoom-20071228a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Fireball Seen Over Oregon, California and Nevada
http://www.ktvz.com/Global/story.asp?S=7540645 Fireball has hunters on the trail of meteor's tail By Barney Lerten and Victoria Adelus KTVZ.COM Decmeber 24, 2007 Updated: December 27, 2007 A blazing fireball plummeting toward Earth was seen over a wide area of Central Oregon, Northern California and Nevada as night fell on Christmas Eve. Several spotters say they saw it break apart into three fiery streaks of light, but a meteorite hunter says there's little if any chance a blazing rock from space might have reached the ground and could be found. While the special timing of the event brings to mind a certain, special star to the east - or even Santa's rocket-powered sleigh thundering across the sky - Dick Pugh, a long-time expert on meteors and meteorites, says he'd like to hear from those who saw - or hopefully heard - the heavenly sight. If meteorite-hunter Pugh of Portland State University hears from enough people and gathers enough data to figure an approximate location - mighty big ifs - then he could beat the mighty odds and find what would be the first known meteorite to be discovered east of the Oregon Cascades. But after hearing from spotters from Sisters, Redmond and Burns to Klamath Falls and San Jose, Calif., Pugh said Wednesday the odds were even slimmer of locating anything that could have fallen to Earth. Several people - perhaps many more - around Deschutes and Crook counties said they saw the fireball streaking toward the ground shortly after 5 p.m. on Monday evening. So did several people near Reno, Nev., meaning it's possible those who thought it was blazing toward Earth close by instead saw something many miles away. A Deschutes County 911 dispatcher reported getting probably five to six calls regarding sightings of the fireball One of our (sheriff's) deputies saw it out in Cloverdale, near Sisters, the dispatcher said, but nobody pinpointed the location, as the sightings came from all over the county. Perhaps the most detailed sighting report came from Keith Clinton, who lives on Gosney Road east of Bend. Around 5 p.m. this evening, a large bright green fireball descended out of the cloudless sky east of Bend, Clinton wrote to NewsChannel 21. Clearly visible from Gosney Road, it was traveling at a steep angle from west to east. At about 10 degrees above the horizon, it turned yellow as it exploded, breaking into several pieces, Clinton added. Given the trajectory, my estimation is that the pieces probably fell somewhere between Bend and Burns, although other sightings will be needed to triangulate and make a closer determination. Clinton told NewsChannel 21 Wednesday, I knew immediately what it was, but of course, I figured if I told anybody they'd think I was a crackpot talking about Santa Claus coming out of the sky. Clinton says he was sitting in his living room when he saw the fireball plummet toward the ground. All of a sudden, through the window, I saw this green fireball come streaking out of the sky,said Clinton. Spencer Krueger told NewsChannel 21's Christian Boris by e-mail that his wife saw a fist-sized flaming orange ball with a tail appearing to fall near the road she was on, northwest of Redmond. Virginia Green of Redmond said she and her husband Dan saw the orange fireball with a tail falling toward Earth around 5:20 p.m. as they headed to the Powell Butte Christian Church for a Christmas Eve gathering. They, too, said it exploded into at least a couple of pieces. Meanwhile, Crook County sheriff's scanner traffic indicated someone on the O'Neil Highway about five miles west of Prineville thought he saw a meteorite crash to the ground. The report was of a flash in the sky and that object grew brighter again as it fell below the rimrock on the horizon. Just to be safe, authorities checked with the Redmond Airport to see if any small planes had gone off radar screens or gone missing, but nothing of the sort was reported. Another report from a Prineville apartment-dweller of three bright-colored lights traveling east to southwest in the sky apparently was unrelated, a dispatcher said. But perhaps the streaking fireball only appeared to be that close. Around the same time, observers in an area near Spanish Springs, north of Reno, Nev., reported seeing a bright red, blue and yellow light falling from the sky. A caller who thought it might have been an aircraft said the air speed was not normal for an aircraft and the brightness was not natural, Washoe County sheriff's Sgt. Harry Dixon told the Reno Gazette-Journal. Sheriff's deputies and search and rescue team members searched the area. Some off-duty search and rescue people in the area saw the falling object and believed it was a meteor, Dixon said. Another sighting: Driver on Hwy. 97 near Oregon-Calif. line Dick Pugh of the Cascadia Meteorite Laboratory at Portland State University (http://meteorites.pdx.edu) had received only one direct report of a sighting by Tuesday night, but said he was
[meteorite-list] Couple Find Possible Meteorite in Their Yard in California?
http://www.vvdailypress.com/news/green_4266___article.html/meteorite_piece.html Piece of the heavens Couple find possible meteorite in their yard By PATRICK THATCHER Victorville Daily Press December 31, 2007 It's not everyday that a little piece of the heavens drops right into your front yard, just inches from your front door. That's what Kay and Rick Green of Hesperia believe happened to them. We are pretty sure it is a meteorite, Green said. I've seen them at gun shows and this looks like those. We had been walking right past it for a couple of days before we even noticed it sticking just a little bit above the ground. Green had recently filled in a hole at the location where the supposed meteorite had landed and, although he noticed something just barely peeking above the ground, he and his wife didn't think anything of it at first. Then he decided to dig it up. I thought it was a tiny piece. I was surprised to see how big it was. What he dug up was a solid piece of material about the size of a head of cabbage, bearing the characteristics of a meteorite. Green put it on a scale, and it weighed a little more than 5 pounds. Without using expert analysis but referring to Web sites that are used for meteorite identification, Green determined that the object that landed in his yard has a number of meteorite characteristics, most notably a strong magnetic pull. Other characteristics are its heavy weight for its size, its coloring and contours. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Deep Impact Zooms by Earth on New Year's Eve
December 31, 2007 Media Contact: Lee Tune 240-328-4914 [EMAIL PROTECTED] Deep Impact Zooms by Earth on New Year's Eve (Earth Flyby and Moon Pics Mark Start of New Mission) College Park, Md. -- This New Year's Eve the University of Maryland-led Deep Impact team will again celebrate a holiday in a way that few can match, when their Deep Impact spacecraft buzzesâ the Earth on a flyby that marks the beginning of a more than two-and-a-half-year journey to comet Hartley 2. In 2005, the Deep Impact team, led by University of Maryland astronomer Michael A'Hearn, celebrated July 4th by smashing a probe into comet Tempel 1 to give the world its first look inside a comet. The trip to Hartley 2 is one part of a new two-part mission for the team and its Deep Impact spacecraft. During the first six months of the journey, the Extrasolar Planet Observations and Characterization (EPOCh) mission team will use the larger of the two telescopes on the Deep Impact spacecraft to search for Earth-sized planets around five stars selected as likely candidates for such planets. Upon arriving at the comet the Deep Impact eXtended Investigation (DIXI) will conduct an extended flyby of Hartley 2 using all three of the spacecraft's instruments (two telescopes with digital color cameras and an infrared spectrometer. The name for the new combined mission, EPOXI, is a combination of the names of its component missions (EPOCh + DIXI = EPOXI). The team is using the flyby of Earth to calibrate the spacecrafts instruments for the new mission and to help slingshot it on the way toward Hartley 2. Although the spacecraft will come closest to the Earth on New Year's Eve, the Maryland-led team has already begun its calibration work. On Saturday, 29 December, two days before its close flyby of Earth, the Deep Impact flyby spacecraft made observations of the moon to calibrate its instruments for its new mission, EPOXI,â said A'Hearn. Some calibrations are obtainable only on a bright, large source, like the moon when reasonably close to it. It looks as though everything operated just as the science team asked it to operate and you can't ask for anything better than that,â he said. 'This Earth gravity assist provided a unique opportunity for us to calibrate our instruments using the Moon,â said Jessica Sunshine, a senior research scientist at the University of Maryland. In particular, the Moon is very useful because it fills the entire field of view of the infrared spectrometer. The results show that our spacecraft pointing and commanding was spot on. We also made measurements which will allow us to cross-calibrate our instruments with telescopic data and, in the very near future, with a wealth of lunar measurements from new orbiting spacecraft. These data will significantly improve the science from EPOCh observations of Earth and the DIXI flyby of comet Hartley 2, as well as from Deep Impact's prime mission to comet Tempel 1, said Sunshine who is deputy principal investigator on DIXI. Past releases with more information about the mission can be found on the University of Maryland's Newsdesk Web site: http://www.newsdesk.umd.edu/scitech/release.cfm?ArticleID=1564 To see all UM Deep Impact releases search for Deep Impact using the search box in the upper right portion of the page. Images of the moon taken by the Deep Impact spacecraft and updates about the mission can be seen on the web site for the new EPOXI mission: http://epoxi.umd.edu/ The DeepImpact Web site is: http://deepimpact.umd.edu/ For people in the United States, the Deep Impact spacecraft generally will be below the horizon during the nighttime hours on New Years Eve and New Year's day and thus not visible, but check the EPOXI site for detailed viewing information. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] New Observations Slightly Decrease Mars Impact Probability (Asteroid 2007 WD5)
http://neo.jpl.nasa.gov/news/news154.html New Observations Slightly Decrease Mars Impact Probability Don Yeomans, Paul Chodas and Steve Chesley NASA/JPL Near-Earth Object Program Office January 2, 2008 Additional position observations for asteroid 2007 WD5 taken on December 29 through January 2 have been used to improve the accuracy of the asteroid's orbit. As a result, the range of possible paths past Mars has narrowed by a factor of 3 and the most likely path has moved a little farther away from the planet, causing the Mars impact probability to decrease slightly to 3.6% (about one chance in 28). The new positional observations were made using the 2.4 meter telescope at New Mexico Tech's Magdalena Ridge Observatory and reported by astronomer Bill Ryan. It seems likely that as additional observations further shrink the uncertainty region of this asteroid, the region will no longer intersect Mars and the impact probability will quickly drop to zero. [Graphic] Updated Uncertainty Region for 2007 WD5 at encounter with Mars, shown as white dots. The thin white line is the orbit of Mars. The blue line traces the motion of the center of the uncertainty region, which is the most likely position of the asteroid. Note that the scale is considerably finer than it has been in past diagrams __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Bright Object Seen Streaking Across California Sky
http://www.redding.com/news/2008/jan/03/ufo-sighting-firemen-go/ UFO sighting? Firemen go toward the light By Kimberly Ross Redding Record Searchlight January 3, 2008 A Christmas Eve flash in the sky over northeastern Shasta County has some speculating about reindeer on fire or season's greetings from little green men. But the celestial light show was probably just a meteorite, said Fall River Mills firefighter Quincy Hatch. Hatch and other firefighters were driving east on Highway 299, east of McArthur, to check on smoke from three burn piles reportedly on the Big Valley summit. On their way, Chief Chuck Bethel and others spotted a bright light and an object streaking across the sky about 7:40 p.m., Hatch said. At first, we thought it might be an airplane that went down, he said. Hatch, also an amateur astronomer, saw the huge flash that lasted three to five seconds, but said he didn't look in time to spot a streaking object in the sky, gone in just a second or two. We had one of the locals up on the ridge drive up in his pickup and ask us if we were searching for the aliens yet, Hatch said with a chuckle. They weren't the only ones who saw the light. As his Burney office co-workers ribbed him with alien greetings of Nanu-nanu and Twilight Zone theme music, Shasta County Sheriff's deputy Jesse Gunsauls grudgingly admitted that he'd seen a large, greenish light coming toward the ground. It surprised him as he drove on Highway 299, on the east side of Hatchet Mountain, but it wasn't like it was flying around or anything, Gunsauls said. It didn't look like a shooting star, he said, and clarified: Do I think it was aliens -- no. Sgt. Anthony Bertain had been driving behind Gunsauls and saw the flash, too. Gunsauls said he guesses it was a meteor, and NASA spokeswoman Dolores Beasley said that conclusion makes sense. Still, that didn't stop Gunsauls' colleagues from teasing that he must have witnessed Rudolph's nose malfunctioning. Gunsauls said he had heard the possible meteorite sparked a spot fire, but Lassen County forestry and fire officials said they had no record of that. Two California Highway Patrol officers and some other residents also reported seeing the flash, Hatch said. The Record Searchlight received an anonymous call that some celestial debris had fallen near the Hat Creek Observatory, where scientists are monitoring for signals of extraterrestrial life. But onsite astronomer Rick Forster said the SETI (Search for Extraterrestrial Intelligence) program there searches for radio waves from deep space, not visual images close to Earth. Those wouldn't be picked up by its equipment. Nevertheless, Forster gets similar reports of objects that are more likely airplanes, planets or twinkling stars, not aliens, he said. It's neat to imagine that that happened and that they're here already, but we take a little more objective stance to the existence of extraterrestrials, he said. Forster's not jaded to those callers, though. I keep hoping that I will witness firsthand what people are reporting, because they sound fascinating. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Deadline for 2007 Nininger Meteorite Award Extended
From: Michelle Minitti, Arizona State University, Tempe, Arizona The Center for Meteorite Studies at Arizona State University announces the extension of the application opportunity for the 2007 Nininger Meteorite Award for undergraduate and graduate students pursuing research in meteoritical sciences. The Nininger Award recognizes outstanding student achievement in the meteoritical sciences as embodied by an original research paper. Papers must cover original research conducted by the student and must have been written, submitted or published between November 16, 2006 and December 31, 2007. The new 2007 Nininger Award application deadline is January 25, 2008. Applicants must be the first, but not sole, author of the paper and must be studying at an educational institution in the United States. The Nininger Award recipient receives $2500 and an engraved plaque commemorating the honor. =46urther information about the Nininger Award and paper submission instructions are located on the Center for Meteorite Studies website: http://meteorites.asu.edu/nininger Questions regarding the application or application process may be sent to: [EMAIL PROTECTED] __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - January 3, 2008
MARS RECONNAISSANCE ORBITER HIRISE IMAGES January 3, 2008 o Jumbled Flow Patterns http://hirise.lpl.arizona.edu/PSP_006278_2225 o Gullies with Meanders http://hirise.lpl.arizona.edu/PSP_006261_1410 o Lineated Valley Fill http://hirise.lpl.arizona.edu/PSP_006252_2220 o Dust Devil Tracks and Barchan Dunes in Terra Cimmeria http://hirise.lpl.arizona.edu/PSP_006248_1235 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA To Find Most Earth-Threatening Asteroids By End of 2008
http://www.computerworld.com/action/article.do?command=viewArticleBasicarticleId=9055040intsrc=hm_list NASA to find most Earth-threatening asteroids by end of 2008 But Mars asteroid, with a 1-in-25 chance of hitting the Red Planet, illustrates broader threat Patrick Thibodeau Computerworld January 03, 2008 -- By the end of this year, NASA hopes to find about 90% of the largest asteroids that could potentially strike Earth, a blast that could throw dust into the atmosphere and cause firestorms and acid rain. These asteroids can be as large as mountains but are at least 1 kilometer (3,280.8 feet) in diameter. NASA estimates that 900 of these objects are in potentially hazardous range of Earth. But the more immediate threat is from much smaller asteroids, such as the asteroid that has a 1-in-25 chance of hitting Mars on Jan. 30. The asteroid, which has the unglamorous name of 2007 WD5, is only 50 meters (164 feet) and is barely a chip off the massive, 10-kilometer-wide (6.2 miles) asteroid that wiped out the dinosaurs some 65 million years ago. Small, yes, but such an asteroid has the explosive force of a 10-megaton nuclear weapon. There are thought to be about 75,000 potentially hazardous asteroids larger than 50 meters, and the vast majority remains undiscovered, Donald Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif., said in an e-mail response to questions. Hence, at the moment, we would not have much warning time prior to a collision. That's the bad news. But the good news is that an object of this size would only cause local damage if it hit, or exploded above, a populated area, which seems unlikely, Yeomans said. Such a strike is unlikely given that two-thirds of the Earth is covered by ocean, he said. A 50-meter asteroid, similar to the one inbound to Mars, will hit Earth once every 500 to 1,000 years, according to Yeomans. This is the same size of the object that struck Tunguska, Siberia, 100 years ago. The Tunguska object disintegrated in the earth's atmosphere, but its blast flattened and scorched trees over an area of some 800 square miles. The Mars asteroid is traveling at 30,000 miles per hour, and a strike could create a crater more than a half-mile wide. But the U.S. isn't searching for the smaller, potentially hazardous asteroids, even though in 2005 Congress directed NASA to find by 2020 potentially hazardous objects of 140 meters or larger. A midsize object of 140 meters (459.3 feet) or larger, with an impact energy of 100 megatons or more, can be expected to hit Earth once every 5,000 years -- a 1% probability of impact every 50 years. In contrast, 1-kilometer or larger asteroids have a mean impact frequency of about once every 500,000 years, according to testimony by Yeomans in November on near-Earth objects before the U.S. House Committee on Science and Technology. Congress didn't set aside money for the expanded asteroid hunt, and out of NASA's annual budget of about $17 billion, it spends just $4.1 million to find potentially hazardous near-Earth objects. Russell Rusty Schweickart, a former astronaut, is now chairman of the B612 Foundation in Sonoma, Calif., which has been pushing NASA and Congress since 2001 to develop a comprehensive plans for dealing with asteroids with our name on it that includes a deflection plan. The reality is we have the knowledge to be able to protect life on Earth from this happening, Schweickart said. If we were really responsible, if we really set about his process ... we could essentially preclude any substantial asteroid from ever hitting Earth again. Schweickart said the Mars asteroid will cause thoughtful people to realize that this happens. The nearest known risk to Earth is the asteroid 99942 Apophis, a 400-meter (1,300 feet) asteroid that has an impact probability of 1-in-45,000 in 2036. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Stardust Formed Close To Sun
https://publicaffairs.llnl.gov/news/news_releases/2008/NR-08-01-01.html News Release Contact: Anne M. Stark Phone: (925) 422-9799 E-mail: [EMAIL PROTECTED] FOR IMMEDIATE RELEASE January 3, 2008 NR-08-01-01 Stardust formed close to sun LIVERMORE, Calif. -- Samples of the material picked up during the NASA Stardust mission indicate that parts of the comet Wild 2 actually formed in an area close to the sun. New research by an international collaboration including Livermore researcher Saša Bajt analyzed noble gases within Stardust samples.The helium and neon isotope analysis suggests that some of the Stardust grains match a special type of carbonaceous material found in meterorites; hence both must have spent time in the same gas reservoir, which was close to the sun. About 10 percent of the mass of Wild 2 is estimated to be from particles transported out from hot inner zones to the cold zone where Wild 2 formed. The paper concludes that this is how these grains with unusual isotope ratios go incorporated into a comet. Earlier research showed that the comet formed in the Kuiper Belt, outside the orbit of Neptune, and only recently entered the inner regions of the solar system. Wild 2 spent most of its life orbiting in the Kuiper Belt, far beyond Neptune, and in 1974 had a close encounter with Jupiter that placed it into its current orbit. The Stardust spacecraft's seven-year mission returned to earth in January 2006 with particles that are the same material that accreted along with ice to shape the comet about 4.57 billion years ago, when the sun and planets formed. But during its lifetime, Wild 2 gathered material that formed much closer to the sun. And the new research, which appears in the Jan. 4 issue of the journal Science, shows that some of the particles in Stardust are consistent with the early solar nebula. The unusual isotope ratio of helium and neon demonstrate that materials in comet Wild 2 had been much closer to the young sun than previously expected, Bajt said. Bajt, who studied tracks in aerogel caused by cometary particles rich in noble gases, used infrared spectroscopy, which is very sensitive in detecting organic molecules. She found none, at least not in the pieces of aerogel she examined. The group concluded that the carriers of the noble gases must be the refractory metal-metal sulfide-metal carbide grains, unlike what many expected would be a meteoritic Q-phase, which is known to be organic. That's the first-order finding of the paper, and it's a rather startling one, said lead author Robert Pepin from the University of Minnesota. The second conclusion is that the ion irradiation is the only known mechanism that could load the grains (by ion implantation) to the very high concentrations based on mass density estimates from X-ray absorption spectroscopy by Andrew Westphal and his team at the (Space Science Laboratory, UC Berkeley. Noble gases are excellent tracers of contributions from various solar system volatile reservoirs and of physical processing of gases acquired from these reservoirs. Their elemental and isotopic compositions in primitive meteorites differ from those in the Sun. Planetary atmospheres display noble gas signatures distinct from both solar and meteoritic patterns. X-ray absorption spectroscopy in the current study showed that the grains are composed primarily of high-temperature metal. The X-ray and isotopic analyses point to gas acquisition in a hot, high-ion flux nebular environment close to the young sun. Stardust is a part of NASA's series of Discovery missions and is managed by the Jet Propulsion Laboratory. Stardust launched in February 1999 and set off on three giant loops around the sun. It began collecting interstellar dust in 2000 and met Wild 2 in January 2004, when the spacecraft was slammed by millions of comet particles, nearly halting the mission. It is the first spacecraft to safely make it back to Earth with cometary dust particles in tow. Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] What Would Happen If Asteroid Hits Mars
http://www.foxnews.com/story/0,2933,320410,00.html What Would Happen If Asteroid Hits Mars By Leonard David space.com January 4, 2008 The possibility of an asteroid walloping the planet Mars this month is whetting the appetites of Earth-bound scientists, even as they further refine the space rock's trajectory. The space rock in question - Asteroid 2007 WD5 - is similar in size to the object that carved Meteor Crater into northern Arizona some 50,000 years ago and is approaching Mars at about 30,000 miles per hour (48,280 kph). Whether the asteroid will actually hit Mars or not is still uncertain. Such an impact, researchers said, would prove an awesome blow for planetary science since NASA's Mars Reconnaissance Orbiter (MRO) and a flotilla of other spacecraft are already in position to follow up any impact from orbit. An impact that we could witness/follow-up with MRO would be truly spectacular, and could tell us much about the hidden subsurface that could help direct a search for life or life-related molecules, said John Rummel, NASA's senior scientist for astrobiology at the agency's Washington, D.C., headquarters. Observations of the asteroid between Dec. 29 and Jan. 2 allowed astronomers to slightly lower the space rock's odds of striking Mars to about 3.6 percent (down from 3.9), giving the object a 1 in 28 chance of hitting the planet, according to Tuesday report from NASA's Near Earth-Object program office at the Jet Propulsion Laboratory in Pasadena, Calif. More observations may further reduce the asteroid's impact chances to nil, NEO officials said. The space rock's refined course stems from observations by astronomers at New Mexico Tech's Magdalena Ridge Observatory. But if WD5 does smack into Mars, some astronomers have a fair idea of what havoc it may spawn. The likely strike zone would be near the equator, but to the north of the current position of NASA's Opportunity rover at Victoria Crater, NASA officials have said. Mark Boslough, a collision dynamics expert at New Mexico's Sandia National Laboratory, said the atmosphere at Mars' surface is similar to that of Earth at an altitude of 12 miles (20 km). Some space rocks that target Earth explode under the pressure created as they stream into our atmosphere. But they tend not to explode until much below the 12-mile mark. So this won't be an airburst, Boslough said. It will either hit the ground intact and make a single crater, or break up and generate a cluster of craters. The collision, were it to occur, could also create a visible dust plume as ejecta is lofted high into the martian atmosphere, he said. The resulting crater could reach more than a half-mile (0.8-km) in diameter, or about the size of the Opportunity rover's Victoria home, NASA added. Boslough's break-up scenario is reminiscent of Comet P/Shoemaker-Levy 9, which broke into more than 20 fragments as it neared Jupiter in 1994, then repeatedly pummeled the gas giant over the course of six days. The resulting impact scars were visible to telescopes on Earth, in orbit and NASA's Galileo probe, which was circling Jupiter at the time of the collision. Like Galileo at Jupiter, NASA's MRO probe and its High-Resolution Imaging Experiment (HiRISE) camera would be in prime position for a martian collision. With its ability to resolve objects three feet (one meter) across, HiRISE as been billed as the most powerful camera ever sent to study Mars. If the asteroid hits Mars, we'll get a great look at the crater within a few days of impact, said HiRISE principal investigator Alfred McEwen of the University of Arizona's Lunar and Planetary Laboratory in Tucson. SPACE.com Staff Writer Tariq Malik contributed to this report from New York City. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images: December 31, 2007 - January 4, 2008
MARS ODYSSEY THEMIS IMAGES December 31, 2007 - January 4, 2008 o Channels (Released 31 December 2007) http://themis.asu.edu/zoom-20071231a o Timbuktu (Released 01 January 2008) http://themis.asu.edu/zoom-20080101a o Confined Flow (Released 02 January 2008) http://themis.asu.edu/zoom-20080102a o Dust Devil Tracks (Released 03 January 2008) http://themis.asu.edu/zoom-20080103a o Wind Power (Released 04 January 2008) http://themis.asu.edu/zoom-20080104a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Red Dust in Planet-Forming Disk May Harbor Precursors to Life
http://www.ciw.edu/news/red_dust_planet_forming_disk_may_harbor_precursors_life For Immediate Release January 3, 2008 Contact: John Debes 1-202-478-8862, [EMAIL PROTECTED] PIO Source: Alan Cutler 1-202-939-1142 [EMAIL PROTECTED] For copies of the paper go to http://arxiv.org/abs/0712.3283 Red Dust in Planet-Forming Disk May Harbor Precursors to Life Washington, DC - Astronomers at the Carnegie Institution have found the first indications of highly complex organic molecules in the disk of red dust surrounding a distant star. The eight-million-year-old star, known as HR 4796A, is inferred to be in the late stages of planet formation, suggesting that the basic building blocks of life may be common in planetary systems. In a study published in the current Astrophysical Journal Letters, John Debes and Alycia Weinberger of the Carnegie Institutionâs Department of Terrestrial Magnetism with Glenn Schneider of the University of Arizona report observations of infrared light from HR 4796A using the Near-Infrared Multi-Object Spectrometer aboard the Hubble Space Telescope. The researchers found that the spectrum of visible and infrared light scattered by the starâs dust disk looks very red, the color produced by large organic carbon molecules called tholins. The spectrum does not match those of other red substances, such as iron oxide. Tholins do not form naturally on present-day Earth because oxygen in the atmosphere would quickly destroy them, but they are hypothesized to have existed on the primitive Earth billions of years ago and may have been precursors to the biomolecules that make up living organisms. Tholins have been detected elsewhere in the solar system, such as in comets and on Saturnâs moon Titan, where they give the atmosphere a red tinge. This study is the first report of tholins outside the solar system. Until recently itâs been hard to know what makes up the dust in a disk from scattered light, so to find tholins this way represents a great leap in our understanding, says Debes. HR 4796A is located in the constellation Centaurus, visible primarily form the southern hemisphere. It is about 220 light years from Earth. The discovery of its dust disk in 1991 generated excitement among astronomers, who consider it a prime example of a planetary system caught in the act of formation. The dust is generated by collisions of small bodies, perhaps similar to the comets or asteroids in our solar system, and which may be coated by the organics. These planetesimals can deliver these building blocks for life to any planets that may also be circling the star. Astronomers are just beginning to look for planets around stars much different from the Sun. HR 4796A is twice as massive, nearly twice as hot as the sun, and twenty times more luminous than the Sun, says Debes. Studying this system provides new clues to understanding the different conditions under which planets form and, perhaps, life can evolve. This research is based on observations with the NASA/ESA Hubble Space Telescope and was supported by NASA and the NASA Astrobiology Institute. The Carnegie Institution (www.CIW.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Vatican Astonomers To Move To Bigger, More Modern Facilities
http://www.catholicnews.com/data/stories/cns/0707310.htm Vatican astronomers to move to bigger, more modern facilities By Carol Glatz Catholic News Service December 21, 2007 VATICAN CITY (CNS) -- After more than half a century based at the papal palace in Castel Gandolfo, the Vatican's astronomers will be moving to bigger, more modern facilities. The astronomers' new offices and residences still will be located on the grounds of the papal summer residence in the hill town of Castel Gandolfo, about 15 miles south of Rome, but they will be in a completely renovated convent nestled in the papal gardens. This is going to be a great improvement for carrying out the astronomers' work and studies and the new residences will be a whole lot more comfortable, said U.S. Jesuit Brother Guy Consolmagno. Work has not yet begun on the new headquarters, so the relocation is not likely to occur before next fall, he said. While the papal palace, where the observatory and two powerful telescopes are located, is a beautiful, historical building dating back to the 1500s, it's also freezing in the wintertime and too hot in the summer, the Vatican astronomer told Catholic News Service Dec. 21. The Jesuit community that works there can number up to 14 people in the summer months, but the facility only has one shower, he said. Vatican officials had been considering moving the Jesuit astronomers out of the papal residence for several years, said a statement by the Jesuit curia earlier this year. The needs of papal quarters, where large crowds gather for audiences and where dignitaries visit the pope even in summer, are not easily combined with a residence for Jesuits engaged in study, teaching and research, it said. The Jesuits have been entrusted with the Vatican Observatory since 1935, when Pope Pius XI decided to move the observatory from the Tower of the Winds not far from the papal apartment in the Vatican to the papal summer residence in Castel Gandolfo. This newest plan to relocate within Castel Gandolfo had some speculating that Jesuit stargazers were being kicked out, as one Italian newspaper headline reported Dec. 20. The Jesuits and Brother Consolmagno disagreed. The Jesuit brother said the enormous effort the Vatican is putting into planning and renovating the new facilities is a sign of just how much they're supporting our continued presence here. The Jesuits said in their statement that giving the astronomers a new headquarters is a confirmation of the importance attributed by the Holy Father to the work being carried out by them. The Vatican astronomers' new facilities will cover two stories with residences on one floor and, on the bottom floor, brand new offices, laboratories, a museum, a library, a large classroom for their summer school program and additional space for the summer students' use. We're all pretty happy with the way they've planned things out, Brother Consolmagno said. He said after they move to their new quarters they will still have access to the two large telescopes located on the roof of the papal palace as well as access to some adjoining rooms and an office. He said the telescopes are not used very often in the summer while the pope is there because the nights are short, giving astronomers reduced viewing time. The Vatican Observatory's Zeiss refractor telescope, built in 1935, also is getting ready for a face-lift. Brother Consolmagno said in a Dec. 21 interview with the Orlando Sentinel newspaper in Florida that the Jesuit astronomers have invited Nate Lust, a recent astronomy graduate of the University of Central Florida, to help them see if he can rescue some beautiful old telescopes with some cutting-edge technology. Lust was to head to Castel Gandolfo in January to see if an electric camera and other technology he developed can help tackle the problem of light pollution, which got so bad for the Vatican astronomers that they set up a second research center in 1981 in the desert of southern Arizona so they could carry out their observational work. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Impact Seems Less Likely (Asteroid 2007 WD5)
http://neo.jpl.nasa.gov/news/news155.html Mars Impact Seems Less Likely Steve Chesley, Paul Chodas and Don Yeomans NASA/JPL Near-Earth Object Program Office January 8, 2008 We have updated the orbit of 2007 WD5 using new observations from the 3.5-meter telescope at the Calar Alto Observatory in Spain. This update also incorporates refinements to the Sloan precovery observations mentioned previously. While the best estimate of close approach distance remains steady at about 30,000 km, the uncertainty in position at the close approach has decreased by a factor of three. As a result, the impact probability estimate has fallen to 2.5%, or 1-in-40 odds. If the estimated miss distance remains stable in future updates, the impact probability will continue to fall as continuing observations further constrain the uncertainties. [Graphic] Updated Uncertainty Region for 2007 WD5 at encounter with Mars, shown as white dots. The thin white line is the orbit of Mars. The blue line traces the motion of the center of the uncertainty region, which is the most likely position of the asteroid. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Forget the Meteorites - It Was Insects That Did For The Dinosaurs
http://www.guardian.co.uk/science/2008/jan/07/dinosaurs Forget the meteorites - it was insects that did for the dinosaurs James Randerson The Guardian (United Kingdom) January 7 2008 They were the most imposing and terrifying creatures that have ever walked on the surface of the Earth, but according to a new theory the dinosaurs may have been pushed towards extinction 65m years ago by humble insects. During the later part of the dinosaurs' dominion over the land, insects underwent an explosion in diversity and in the process dealt a double whammy to the lumbering giants - they spread disease and contributed to a transformation of vegetation which the plant-eating reptiles failed to adapt to. The hypothesis is laid out in a new book by entomologists George and Roberta Poinar. George Poinar is a professor of zoology at Oregon State University. We can't say for certain that insects are the smoking gun, but we believe they were an extremely significant force in the decline of the dinosaurs, said Poinar. Our research with amber shows that there were evolving, disease-carrying vectors in the Cretaceous [period], and that at least some of the pathogens they carried infected reptiles. This clearly fills in some gaps regarding dinosaur extinctions. In the gut of one biting insect preserved in amber - fossilised tree sap - from that era, the team has found the pathogen that causes the parasitic disease leishmaniasis, and in another they found a type of malaria parasite that infects birds and lizards. By inspecting fossilised dinosaur faeces, the team also found parasitic microbes that are carried by insects. Apart from spreading disease, the insects were busy pollinating flowering plants. These gradually took over from seed ferns, cycads and gingkoes. If herbivorous dinosaurs could not adapt to this new diet they would have gone hungry. Poinar believes that the most popular theory for the dinosaurs' demise - that a meteorite impact changed the global climate - falls short because the extinction took too long. Other geologic and catastrophic events certainly played a role. But by themselves, such events do not explain a process that in reality took a very, very long time, perhaps millions of years. Insects and diseases do provide that explanation. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Object Seen Streaking Over Florida
http://www.myfoxorlando.com/myfox/pages/News/Detail?contentId=5419908version=1locale=EN-USlayoutCode=TSTYpageId=3.2.1 What was that flying object? MyFox Orland January 7, 2008 POINCIANA, Fla. (WOFL FOX 35, Orlando) -- FOX 35 viewer, Alexandra Gregory captured these spectacular images of an object -- what appears to be a meteor -- streaking through the sky on Tuesday, January 7, as seen from Poinciana. According to NASA, beginning each New Year and lasting for nearly a week, the Quadrantid Meteor Shower can be witnessed across the night sky for nearly all viewers around the world, though Monday's sighting in Central Florida has not been confirmed as being related this annual interstellar phenomenon. The term meteor comes from the Greek meteoron, meaning phenomenon in the sky. Solarviews.com describes a meteor as a streak of light produced as matter in the solar system falls into Earth's atmosphere creating temporary incandescence resulting from atmospheric friction. This typically occurs at heights of 50 to 70 miles above Earth's surface. A meteorite is a meteoroid that reaches the surface of the Earth without being completely vaporized. The International Meteorite Collectors Association offers extensive records which show occurrences of meteorites striking man-made objects, animals and even people! You can see a list of such events, including one reported strike in Orlando in 2004, by clicking here. http://imca.repetti.net/metinfo/metstruck.html __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Astrophysicist Raises Odds of Asteroid Strike on Mars (2007 WD5)
http://www.adn.com/news/alaska/story/258025.html UAA researcher gives Mars bad news COLLISION: Astrophysicist raises odds of asteroid strike. By GEORGE BRYSON Anchorage Daily News January 8, 2008 The odds are it will miss. Still, there's a huge asteroid -- a massive rock about 160 feet long -- hurtling toward Mars. Two weeks ago, NASA scientists said the chances it would collide with the Red Planet were 1 in 75. Now they say it's 1 in 28, and astronomers and physicists are beginning to take notice. As they do, the scientists can credit Andrew Puckett, a 30-year-old astrophysicist conducting post-doctoral research at the University of Alaska Anchorage. Working on his own during Christmas break, Puckett discovered archival data that allowed NASA to refine its forecast on what's now being called Asteroid 2007 WD5. When I submitted the information, all I knew was that I was changing the (projected) orbit, Puckett said in a telephone interview Monday. I was sure I would also change the impact odds, but I had no idea whether it would go up or down. So the fact that it went up -- and became a big story -- is just really exciting for me. It might become exciting for a lot of other people as well, says UAA physics and astronomy professor Travis Rector, who supervises Puckett's research -- if the asteroid actually hits Mars. Such an explosion -- a force equivalent to a 3-megaton nuclear bomb -- would leave a crater on Mars about a half mile wide. Exploring it with satellites and terrestrial rovers could allow scientists to answer questions about whether life forms have ever existed on other planets. If you consider the importance of that -- it would be an amazing event if it occurs, Rector said. Typically the odds that any of the asteroids that NASA regularly tracks through its Near Earth Object Program will ever strike home -- or even a neighboring planet -- are tiny, Rector said. They're like 'one in 10,000' and that sort of thing. So it's a very big deal, and it's getting a lot of attention. Scientists began to perk up in November, after 2007 WD5 whizzed past Earth at about 30,000 miles an hour -- then resumed its orbit toward the outer solar system on a trajectory that would take it even closer to Mars. On Dec. 21, the NASA Near Earth Object Program reported the chances that the flying rock might actually hit Mars were about 1.3 percent. But the space agency's revised forecast on Dec. 28 -- using data provided by Puckett -- increased that likelihood to 3.9 percent. How'd he come by such information himself? Last year, after earning a Ph.D. in astronomy and astrophysics while studying comets and asteroids at the University of Chicago, Puckett was hired by UAA to help develop a new physics and astronomy curriculum -- an initiative supported by a $500,000 grant from the National Science Foundation. Separate from that mission, however, he'd continued to pay attention to obscure objects in our solar system -- and on Dec. 21 was startled to hear news of the proximity to Earth of 2007 WD5. (Though it missed us by 5 million miles, Puckett says, that counts as close, in asteroid distance.) Because of his familiarity with tracking asteroids through images available online in the Sloan Digital Sky Survey -- a database principally used to monitor distant galaxies -- Puckett was able to provide earlier plot points for 2007 WD5. After working out some calculations on Christmas Day, he sent his findings to the Minor Planet Center at Harvard. The university, in turn, provided the information to NASA's Jet Propulsion Laboratory in California. Then just before New Year's Day, NASA readjusted the chances the asteroid will strike Mars. Now Puckett is rooting for a direct hit . I hope it happens, he told a UAA publicist last week, noting that such a cataclysm would also draw attention to the general threat asteroids pose toward Earth. The impact here of a meteorite the size of Asteroid 2007 WD5 would devastate a large metropolis, said Donald Yeomans, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, interviewed recently by the Discovery Channel. (An asteroid is a sub-planet-sized object of rock or metal that orbits the Sun; a meteor is an asteroid or meteoroid (if it's small) that penetrates the Earth's atmosphere and catches fire; a meteorite is a meteor that strikes Earth before burning up.) The last time anything the size of the Mars-bound asteroid hit Earth was in 1908, when a fragment of a comet slammed into a forested region of Central Siberia with the force of a nuclear bomb, Puckett said. But vastly larger meteorites that hit Earth eons ago are believed to have caused mass extinctions, including one 65 million years ago that may have killed off all the dinosaurs and launched the age of mammals. If 2007 WD5 misses Mars on this orbit, Puckett said, then it's possible that it could threaten Earth once more -- 81 years from now -- when our orbits align once again.
[meteorite-list] Apollo Astronaut Rusty Schweickart to Speak on Asteroid Impact Threat
From: Bruce Cordell, Ph.D. Dean, Natural Sciences Fullerton College (714) 992-7106 [EMAIL PROTECTED] APOLLO ASTRONAUT RUSTY SCHWEICKART TO SPEAK ON ASTEROID IMPACT THREAT In early February, 2008, the Apollo 9 Astronaut will present a public talk, Asteroid Impact - Protecting the Earth at Fullerton College. The Schweickart event - open to the public and free of charge - will occur on Tuesday, February 5, 2008 in the Wilshire Auditorium at 7 pm at Fullerton College [in Fullerton, Calfornia]. Wilshire Auditorium is located at 330 N. Lemon St. at the southeast corner of Lemon St. and Chapman Ave. As part of NASA's preparations for the first manned Moon landing, Schweickart was the lunar module pilot on Apollo 9 and performed the first orbital tests of the vehicle that would later take humans down to the lunar surface. During his 46 minute space walk in Earth orbit, Schweickart also tested the portable life support system that was used by astronauts on the Moon. Rusty Schweickart serves today as Chairman of the Board (and co-founder) of the B612 Foundation, a non-profit private group that seeks to protect the Earth from future asteroid impacts. The major concern is an estimated 300+ near-Earth asteroids over 1 km in diameter and another 100,000 smaller bodies (above 100 meters) whose orbits are currently unknown, but which could pose a threat to Earth. For example, a 1 km asteroid hitting Earth would explode with the energy of 70,000 megatons (MT) of TNT; this dwarfs the largest H-bomb ever exploded by humans (50 MT), and would threaten life on Earth. A 100 meter body that actually impacted in 1908 in Siberia released 12 MT of energy. The B612 Foundation is the first organization to seriously address this threat. Rather than using nuclear bombs to fragment the asteroid, they propose an Asteroid Tugboat; i.e., attaching a low-thrust rocket to the incoming asteroid and gently nudging it away from Earth. Schweickart's distinguished post-astronaut career includes serving for two years as the Governor of California's assistant for science and technology. He was also appointed as Commissioner of Energy for the State of California and served on the Commission for five and a half years. In 1998, Schweickart retired from ALOHA Networks, Inc. where he served as President and CEO. ALOHA was a data communications company specializing in high performance, wireless internet access equipment. Rusty Schweickart is presented by the Fullerton College Foundation, Inc. and the Center for the Future at Fullerton College. More information about this event and other public space events this Spring, 2008 is at: http://fcfutures.fullcoll.edu/futures.events.s.08.htm __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - January 9, 2008
MARS RECONNAISSANCE ORBITER HIRISE IMAGES January 9, 2008 o Winslow Crater: A Not-So-Fresh, Fresh Crater http://hirise.lpl.arizona.edu/PSP_004313_1760 o Central Pit Crater http://hirise.lpl.arizona.edu/PSP_005409_1530 o Hills and Cones in Utopia http://hirise.lpl.arizona.edu/PSP_003573_2110 o Gullies with Sharp Color Contrasts http://hirise.lpl.arizona.edu/PSP_003492_1405 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] 2007 WD5 Mars Collision Effectively Ruled Out - Impact Odds now 1 in 10, 000
http://neo.jpl.nasa.gov/news/news156.html 2007 WD5 Mars Collision Effectively Ruled Out - Impact Odds now 1 in 10,000 Steve Chesley, Paul Chodas and Don Yeomans NASA/JPL Near-Earth Object Program Office January 9, 2008 Since our last update, we have received numerous tracking measurements of asteroid 2007 WD5 from four different observatories. These new data have led to a significant reduction in the position uncertainties during the asteroid's close approach to Mars on Jan. 30, 2008. As a result, the impact probability has dropped dramatically, to approximately 0.01% or 1 in 10,000 odds, effectively ruling out the possible collision with Mars. Our best estimate now is that 2007 WD5 will pass about 26,000 km from the planet's center (about 7 Mars radii from the surface) at around 12:00 UTC (4:00 am PST) on Jan. 30th. With 99.7% confidence, the pass should be no closer than 4000 km from the surface. [Graphic] Updated Uncertainty Region for 2007 WD5 at encounter with Mars, shown as white dots. The thin white line is the orbit of Mars. The blue line traces the motion of the center of the uncertainty region, which is the most likely position of the asteroid. Image of 2007 WD5 from the University of Hawaii 2.2-meter telescope on Mauna Kea, Hawaii. [Image] Image of 2007 WD5 from the University of Hawaii 2.2-meter telescope on Mauna Kea, Hawaii. The circled dot is the asteroid. Other dots are artifacts from cosmic rays. The stars are trailed because the telescope is tracking the asteroid as it moves among the stars. (Credit: Tholen, Bernardi, Micheli with support from the National Science Foundation). The sequence of updates over the last few weeks has been typical of past potential impact scenarios, with the odds of impact initially surging and later plummeting towards zero. Early on, the uncertainty region is very large and the probability of impact is rather low. As the uncertainty narrows, but still includes the planet, the probability initially increases. But eventually, as in this case, the uncertainty region shrinks to the point that it no longer overlaps the planet, and the probability of impact begins a precipitous decline. This rise and fall of the computed hazard was most notably seen in Dec. 2004 when asteroid 99942 Apophis briefly reached a 2.7% chance of impact with Earth in April 2029. In every case, the height and the timing of the peak probability - and the subsequent decline - cannot be known until the uncertainty region has shrunk to the point where it no longer intersects the planet. NASA's Spaceguard Survey continues searching for Near-Earth Asteroids such as 2007 WD5, endeavoring to discover 90% of those larger than 1 km in size, a goal that should be met within the next few years. Each discovered asteroid is continually monitored for the possibility of impact. For 2007 WD5, these analyses show there is no possibility of impact with either Mars or Earth in the next century. This unfolding story and the present results have been made possible by the tracking efforts of many astronomers at several observatories around the world: * 2007 WD5 was discovered using the Mt. Lemmon 1.5-meter telescope by Andrea Boattini of the University of Arizona's Catalina Sky Survey, which is led by Steve Larson. * Follow-up from archival images taken by the 1.8-meter telescope on Kitt Peak in Arizona were provided by Terrence H. Brezzi of the University of Arizona's Spacewatch Project, which is led by Robert McMillan. * Andy Puckett of the Univ. of Alaska obtained pre-discovery measurements from archival images of the Sloan Digital Sky Survey?s 2.5-meter telescope on Apache Point, NM. * Bill Ryan of New Mexico Tech's Magdalena Ridge Observatory observed 2007 WD5 on several crucial nights, with critical support from university and observatory staff. * Observations from the 6.5-meter Multi-Mirror Telescope (MMT) Observatory in Arizona were provided by a team consisting of Holger Israel (Univ. Bonn), Matt Holman (Harvard/CfA), Steve Larson (Univ. Ariz.), Faith Vilas (MMTO), Cesar Fuentes (Harvard/CfA), David Trilling (Univ. Ariz.) and Maureen Conroy (Harvard/CfA). * The 3.5-meter telescope at the Calar Alto Observatory in Spain provided follow-up through a team consisting of Adriano Campo Bagatin (Univ. Alicante), Gilles Bergond (Calar Alto Obs.), Rene Duffard (Inst. de Astrofisica de Andalucia), Jose Luis Ortiz (Inst. de Astrofisica de Andalucia), Reiner Stoss (Obs. Astronomico de Mallorca and Astronomisches Rechen-Institut) and Javier Licandro (Inst. de Astrofisica de Canarias). * Fabrizio Bernardi, Marco Micheli and Dave Tholen of the Univ. of Hawaii Institute for Astronomy observed the asteroid at its faintest using the 2.2-meter UH telescope on Mauna Kea in Hawaii. __
[meteorite-list] MESSENGER To Make Historic Flyby of Mercury
Jan. 10, 2008 Dwayne Brown Headquarters, Washington 202-358-1726 [EMAIL PROTECTED] Paulette Campbell Johns Hopkins University Applied Physics Laboratory, Laurel, Md. 240-228-6792 [EMAIL PROTECTED] RELEASE: 08-003 NASA SPACECRAFT TO MAKE HISTORIC FLYBY OF MERCURY LAUREL, Md. - On Monday, Jan. 14, a pioneering NASA spacecraft will be the first to visit Mercury in almost 33 years when it soars over the planet to explore and snap close-up images of never-before-seen terrain. These findings could open new theories and answer old questions in the study of the solar system. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft, called MESSENGER, is the first mission sent to orbit the planet closest to our sun. Before that orbit begins in 2011, the probe will make three flights past the small planet, skimming as close as 124 miles above Mercury's cratered, rocky surface. MESSENGER's cameras and other sophisticated, high-technology instruments will collect more than 1,200 images and make other observations during this approach, encounter and departure. It will make the first up-close measurements since Mariner 10 spacecraft's third and final flyby on March 16, 1975. When Mariner 10 flew by Mercury in the mid-1970s, it surveyed only one hemisphere. This is raw scientific exploration and the suspense is building by the day, said Alan Stern, associate administrator for NASA's Science Mission Directorate, Washington. What will MESSENGER see? Monday will tell the tale. This encounter will provide a critical gravity assist needed to keep the spacecraft on track for its March 2011 orbit insertion, beginning an unprecedented yearlong study of Mercury. The flyby also will gather essential data for mission planning. During this flyby we will begin to image the hemisphere that has never been seen by a spacecraft and Mercury at resolutions better than those acquired by Mariner 10, said Sean C. Solomon, MESSENGER principal investigator, Carnegie Institution of Washington. Images will be in a number of different color filters so that we can start to get an idea of the composition of the surface. One site of great interest is the Caloris basin, an impact crater about 800 miles in diameter, which is one of the largest impact basins in the solar system. Caloris is huge, about a quarter of the diameter of Mercury, with rings of mountains within it that are up to two miles high, said Louise Prockter, the instrument scientist for the Mercury Dual Imaging System at the Johns Hopkins University Applied Physics Laboratory in Laurel. Mariner 10 saw a little less than half of the basin. During this first flyby, we will image the other side. MESSENGER's instruments will provide the first spacecraft measurements of the mineralogical and chemical composition of Mercury's surface. It also will study the global magnetic field and improve our knowledge of the gravity field from the Mariner 10 flyby. The long-wavelength components of the gravity field provide key information about the planet's internal structure, particularly the size of Mercury's core. The flyby will provide an opportunity to examine Mercury's environment in unique ways, not possible once the spacecraft begins orbiting the planet. The flyby also will map Mercury's tenuous atmosphere with ultraviolet observations and document the energetic particle and plasma of Mercury's magnetosphere. In addition, the flyby trajectory will enable unique particle and plasma measurements of the magnetic tail that sweeps behind Mercury. Launched Aug. 3, 2004, MESSENGER is slightly more than halfway through its 4.9-billion mile journey. It already has flown past Earth once and Venus twice. The spacecraft will use the pull of Mercury's gravity during this month's pass and others in October 2008 and September 2009 to guide it progressively closer to the planet's orbit. Insertion will be accomplished with a fourth Mercury encounter in 2011. The MESSENGER project is the seventh in NASA's Discovery Program of low-cost, scientifically focused space missions. The Applied Physics Laboratory designed, built and operates the spacecraft and manages the mission for NASA. For more information about MESSENGER, visit: http://www.nasa.gov/messenger -end- __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] When Worlds Collide: Have Astronomers Observed the Aftermath of a Distant Planetary Collision?
Public Affairs Office Harvard-Smithsonian Center for Astrophysics Cambridge, Massachusetts For more information, contact: David A. Aguilar Director of Public Affairs Harvard-Smithsonian Center for Astrophysics 617-495-7462 Christine Pulliam Public Affairs Specialist Harvard-Smithsonian Center for Astrophysics 617-495-7463 For Release: Wednesday, January 09, 2008 11:00:00 AM EST Release No.: 2008-01 When Worlds Collide: Have Astronomers Observed the Aftermath of a Distant Planetary Collision? Austin, TX -- Astronomers announced today that a mystery object orbiting a star 170 light-years from Earth might have formed from the collision and merger of two protoplanets. The object, known as 2M1207B, has puzzled astronomers since its discovery because it seems to fall outside the spectrum of physical possibility. Its temperature, luminosity, age, and location do not match up with any theory. This is a strange enough object that it needs a strange explanation, said Eric Mamajek of the Harvard-Smithsonian Center for Astrophysics (CfA). The announcement was made in a press conference at the 211th meeting of the American Astronomical Society. 2M1207B orbits a 25-Jupiter-mass brown dwarf called 2M1207A seen in the direction of the constellation Centaurus. Computer models show that 2M1207A is very young, only about 8 million years old; therefore its companion should also be 8 million years old. At that age, it should have cooled to a temperature of less than 1300 degrees Fahrenheit (1000 Kelvin). However, observations show that 2M1207B is actually about 2400 degrees F (1600 K). The extra heat might be the result of a protoplanetary collision. Most, if not all, planets in our solar system were hit early in their history. A collision created Earth's moon and knocked Uranus on its side, explained Mamajek. It's quite likely that major collisions happen in other young planetary systems, too. Given its temperature, astronomers would expect a certain luminosity for 2M1207B, but it is 10 times fainter than expected. In 2006, astronomers suggested that it is obscured by a dusty, edge-on disk. Mamajek and his colleague, Michael Meyer of the University of Arizona, propose an alternative explanation: 2M1207B is small, only about the size of Saturn, and therefore has a smaller-than-expected surface area radiating energy. They derive a radius of 31,000 miles (50,000 km) for 2M1207B, compared to 37,000 miles (60,000 km) for Saturn. Given typical densities for giant planets, this would give 2M1207B a mass about 80 times Earth (or one-fourth Jupiter). The only plausible way for such a small object to be so hot millions of years after it formed is if it suffered a recent, titanic collision that heated it. The planets in our solar system assembled from dust, rock, and gas, gradually growing larger over millions of years. But sometimes, two planet-sized objects collided catastrophically. For example, the Moon formed when an object about half the size of Mars hit the proto-Earth. If planet formation works the same way in other star systems, then 2M1207B might be the product of a collision between a Saturn-sized gas giant and a planet about three times the size of Earth. The two smacked into each other and stuck, forming one larger world still boiling from the heat generated in the collision. The Earth was hit by something one-tenth its mass, and it's likely that other planets in our solar system were too, including Venus and Uranus, explained Meyer. If that one-tenth scale holds in other planetary systems, then we could be seeing the aftermath of a collision between a 72 Earth-mass gas giant and an 8 Earth-mass planet, even though such collisions are very unlikely. Mamajek also points out that the collision theory is reasonable from a timescale point of view. A 2400-degree, Saturn-sized object would radiate its heat away over about 100,000 years. If the system were billions of years old, it is unlikely that we would be looking at the right time, but since the system is young, the chances are much better that we would catch it shortly after the collision while the hot aftermath is still observable. The collision hypothesis makes several predictions that astronomers can test. Chief among them is a low surface gravity (which depends on a planet's mass and radius). To check this prediction, astronomers will need to get a better spectrum of 2M1207B -- a challenge since it is very faint and very close to the brown dwarf 2M1207A. Others are checking the dusty disk theory by looking for signs of polarization in the light from 2M1207B. More answers should be forthcoming within a year or two. Mamajek emphasized that while a planet collision may not be the correct explanation for the weirdness of 2M1207B, examples of colliding planets are likely to be found by the next generation of ground-based telescopes. Hot, post-collision planets might be a whole new class of objects we will see with the Giant Magellan Telescope. Even if
[meteorite-list] Mars Odyssey THEMIS Images: January 7-11, 2008
MARS ODYSSEY THEMIS IMAGES January 7-11, 2008 o Arcuate Collapse (Released 07 January 2008) http://themis.asu.edu/zoom-20080107a o Ophir Chasma (Released 08 January 2008) http://themis.asu.edu/zoom-20080108a o Landslides (Released 09 January 2008) http://themis.asu.edu/zoom-20080109a o Channels (Released 10 January 2008) http://themis.asu.edu/zoom-20080110a o Wind Action (Released 11 January 2008) http://themis.asu.edu/zoom-20080111a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Epimetheus Revealed
http://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2920 Epimetheus Revealed January 11, 2008 Full-Res: PIA09813 http://photojournal.jpl.nasa.gov/catalog/PIA09813 The Cassini spacecraft's close flyby of Epimetheus in December 2007 returned detailed images of the moon's south polar region. The view shows what might be the remains of a large impact crater covering most of this face, and which could be responsible for the somewhat flattened shape of the southern part of Epimetheus (116 kilometers, or 72 miles across) seen previously at much lower resolution. The image also shows two terrain types: darker, smoother areas, and brighter, slightly more yellowish, fractured terrain. One interpretation of this image is that the darker material evidently moves down slopes, and probably has a lower ice content than the brighter material, which appears more like bedrock. Nonetheless, materials in both terrains are likely to be rich in water ice. The images that were used to create this enhanced color view were taken with the Cassini spacecraft narrow-angle camera on Dec. 3, 2007. The views were obtained at a distance of approximately 37,400 kilometers (23,000 miles) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 65 degrees. Image scale is 224 meters (735 feet) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Korean Scientists Find 3.7 kg Meteorite in Antarctica
http://english.chosun.com/w21data/html/news/200801/200801150010.html Korean Polar Explorers Find Massive Meteorite A team of Korean scientists in Antarctica has discovered a large meteorite weighing 3.7 kg. Digital Chosunilbo January 15, 2008 The Korea Polar Research Institute under the Korea Ocean Research and Development Institute said Monday that the country's second exploration team to Antarctica discovered 13 meteorites in the western Thiel Mountains on Dec. 24, 29 and 30. Last year, the country's first exploration team to the southern continent found five meteorites, but they weighed only between 200 and 400 g. Meteorites, large pieces of rocks from outer space that have landed on Earth, are important in the study of the creation of the solar system and the evolution of the planets. Antarctica accounts for just three percent of the Earth's surface, but over 80 percent or 25,000 of all discovered meteorites have been found there. With a total of 18 meteorites discovered by the two exploration teams, Korea has become the fifth holder of meteorites after the U.S., Japan, China and Italy. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER's First Look at Mercury's Previously Unseen Side
http://messenger.jhuapl.edu/news_room/status_report_01_15_08_2.html MESSENGER Mission News January 15, 2008 MESSENGER's First Look at Mercury's Previously Unseen Side When Mariner 10 flew past Mercury three times in 1974 and 1975, the same hemisphere was in sunlight during each encounter. As a consequence, Mariner 10 was able to image less than half the planet. Planetary scientists have wondered for more than 30 years about what spacecraft images might reveal about the hemisphere of Mercury that Mariner 10 never viewed. On January 14, 2008, the MESSENGER spacecraft observed about half of the hemisphere missed by Mariner 10. This image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=117 was snapped by the Wide Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, about 80 minutes after MESSENGER's closest approach to Mercury (2:04 p.m. EST), when the spacecraft was at a distance of about 27,000 kilometers (about 17,000 miles). The image shows features as small as 10 kilometers (6 miles) in size. This image was taken through a filter sensitive to light near the red end of the visible spectrum (750 nm), one of a sequence of images taken through each of MDIS's 11 filters.. Like the previously mapped portion of Mercury, this hemisphere appears heavily cratered. It also reveals some unique and distinctive features. On the upper right is the giant Caloris basin, including its western portions never before seen by spacecraft. Formed by the impact of a large asteroid or comet, Caloris is one of the largest, and perhaps one of the youngest, basins in the Solar System. The new image shows the complete basin interior and reveals that it is brighter than the surrounding regions and may therefore have a different composition. Darker smooth plains completely surround Caloris, and many unusual dark-rimmed craters are observed inside the basin. Several other multi-ringed basins are seen in this image for the first time. Prominent fault scarps (large ridges) lace the newly viewed region. Other images obtained during the flyby will reveal surface features in color and in much more detail. Collectively, these images and measurements made by other MESSENGER instruments will soon provide a detailed global view of the surface of Mercury, yielding key information for understanding the formation and geologic history of the innermost planet. Additional information and features from this first flyby will be available online at http://messenger.jhuapl.edu/mer_flyby1.html. Following the flyby, be sure to check for the latest released images and science results! MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery/-class mission for NASA. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Life on Earth 'Began on a Radioactive Beach'
http://www.telegraph.co.uk/earth/main.jhtml?view=DETAILSgrid=xml=/earth/2008/01/09/scibeach109.xml Life on Earth 'began on a radioactive beach' By Nic Fleming The Telegraph (United Kingdom) January 9, 2008 Life on Earth began on a radioactive beach, a scientist claimed today. According to computer models, deposits could collect at a beach's high tide mark in sufficient quantity to trigger fission reactions The sifting and collection of radioactive material by powerful tides could have generated the complex molecules that led to the evolution of carbon-based life forms - including plants, animals and humans. While radiation may seem an unlikely candidate to kick-start life because it breaks chemical bonds and splits large molecules, it also crucially provides chemical energy needed to generate some of the basic building blocks of life. Zachary Adam, an astrobiologist at the University of Washington in Seattle, has suggested the collection of radioactive material on a beach as a new theory for the origins of life - to be added to the existing long and varied list of hypotheses. One is its emergence from a primordial soup of simple organic chemicals accumulated on the surface of bodies of water within the hydrogen-rich early atmosphere - formulated in the 1920's by English geneticist J. B. S. Haldane and Russian biochemist Alexander Oparin. Others include early life forming in inorganic clay, the initial energy coming not from chemical reactions but from sunlight or lightening and the arrival of microscopic seeds of terrestrial life on chunks of meteorites or comets, and the intervention of a divine, intelligent designer. In work highlighted in this week's New Scientist magazine, Mr Adam suggests the more powerful tides generated by the moon's closer orbit billions of years ago compared to today could have sorted radioactive material from other sediment. According to his computer models, deposits could collect at a beach's high tide mark in sufficient quantity to trigger the self-sustaining fission reactions - as occur in natural seams of uranium. Mr Adam demonstrated in laboratory experiments that such a deposit could produce the chemical energy to generate some of the molecules in water which produce amino acids and sugars - key building blocks of life - when irradiated. A deposit of a radioactive material called monazite would also release soluble phosphate, another important ingredient for life, into the gaps between sand grains - making it accessible to react in water. Mr Adam told the New Scientist: Amino acids, sugars and [soluble] phosphate can all be produced simultaneously in a radioactive beach environment. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER Reveals Mercury in New Detail
The Johns Hopkins University Applied Physics Laboratory Office of Communications and Public Affairs Laurel, Maryland Media Contacts: Paulette Campbell (240) 228-6792 or (443) 778-6792 [EMAIL PROTECTED] January 16, 2008 FOR IMMEDIATE RELEASE MESSENGER REVEALS MERCURY IN NEW DETAIL As MESSENGER approached Mercury on Jan. 14, the spacecraft's Narrow-Angle Camera on the Mercury Dual Imaging System (MDIS) instrument captured a view of the planet's rugged, cratered landscape illuminated obliquely by the Sun. See the image at http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=118 The large, shadow-filled, double ringed crater to the upper right was glimpsed by Mariner 10 more than three decades ago and named Vivaldi, after the Italian composer. Its outer ring has a diameter of about 200 kilometers (about 125 miles). MESSENGER's modern camera has revealed detail that was not well seen by Mariner 10, including the broad ancient depression overlapped by the lower-left part of the Vivaldi crater. The MESSENGER science team is in the process of evaluating later images snapped from even closer range showing features on the side of Mercury never seen by Mariner 10. It is already clear that MESSENGER's superior camera will tell us much that could not be resolved even on the side of Mercury viewed by Mariner's vidicon camera in the mid-1970s. This MESSENGER image was taken from a distance of about 18,000 kilometers (11,000 miles), about 56 minutes before the spacecraft's closest encounter with Mercury. It shows a region roughly 500 kilometers (300 miles) across, and craters as small as 1 kilometer (0.6 mile) can be seen in this image. Additional information and features from this first flyby will be available online at http://messenger.jhuapl.edu/mer_flyby1.html Check for the latest released images and science results. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as Principal Investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA. ### __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - January 16, 2008
MARS RECONNAISSANCE ORBITER HIRISE IMAGES January 16, 2008 o Intersecting Graben in Utopia Planitia http://hirise.lpl.arizona.edu/PSP_006500_2200 o Dust-Devil Tracks in Southern Schiaparelli Basin http://hirise.lpl.arizona.edu/PSP_006477_1745 o Colliding Dunes in Meridiani Planum http://hirise.lpl.arizona.edu/PSP_006254_1885 o Intra-Crater Deposits in Nilosyrtis http://hirise.lpl.arizona.edu/PSP_006250_2200 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Two New Images from MESSENGER's First Flyby of Mercury
http://messenger.jhuapl.edu/news_room/status_report_01_16_08_2.html MESSENGER Mission News January 16, 2008 [Evening Update] Two New Images from MESSENGER's First Flyby of Mercury Detailed Close-up of Mercury's Previously Unseen Surface Just 21 minutes after MESSENGER's closest approach to Mercury on January 14, 2008, the Narrow Angle Camera (NAC) took this picture http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=119 showing a variety of intriguing surface features, including craters as small as about 300 meters (about 300 yards) across. This is one of a set of 68 NAC images showing landscapes near Mercury's equator on the side of the planet never before imaged by spacecraft. From such highly detailed close-ups, planetary geologists can study the processes that have shaped Mercury's surface over the past 4 billion years. One of the highest and longest scarps (cliffs) yet seen on Mercury curves from the top center down across the right side of this image. (The Sun is shining low from the left, so the scarp casts a wide shadow.) Great forces in Mercury's crust have thrust the terrain occupying the left two-thirds of the picture up and over the terrain to the right. An impact crater has subsequently destroyed a small part of the scarp near the top of the image. This image was taken from a distance of only 5,800 kilometers (3,600 miles) from surface of the planet and shows a region about 170 kilometers (about 100 miles) across. Mercury's Cratered Surface During its flyby of Mercury, the MESSENGER spacecraft acquired high-resolution images of the planet's surface. This image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=120, taken by the Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS), was obtained on January 14, 2008, about 37 minutes after MESSENGER's closest approach to the planet. The image reveals the surface of Mercury at a resolution of about 360 meters/pixel (about 1,180 feet/pixel), and the width of the image is about 370 kilometers (about 230 miles). This image is the 98th in a set of 99 images that were taken in a pattern of 9 rows and 11 columns to enable the creation of a large, high-resolution mosaic of the northeast quarter of the region not seen by Mariner 10. During the encounter with Mercury, the MDIS acquired image sets for seven large mosaics with the NAC. This image shows a previously unseen crater with distinctive bright rays of ejected material extending radially outward from the crater's center. A chain of craters nearby is also visible. Studying impact craters provides insight into the history and composition of Mercury as well as dynamical processes that occurred throughout our Solar System. The MESSENGER Science Team has begun analyzing these high-resolution images to unravel these fundamental questions. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery -class mission for NASA. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER: New Images Shed Light on Mercury's Geological History, Surface Textures
http://messenger.jhuapl.edu/news_room/status_report_01_17_08.html MESSENGER Mission News January 17, 2008 New Images Shed Light on Mercury's Geological History, Surface Textures MESSENGER Reveals Mercury's Geological History Shortly following MESSENGER's closest approach to Mercury on January 14, 2008, the spacecraft's Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) instrument acquired this image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=121 as part of a mosaic that covers much of the sunlit portion of the hemisphere not viewed by Mariner 10. Images such as this one can be read in terms of a sequence of geological events and provide insight into the relative timing of processes that have acted on Mercury's surface in the past. The double-ringed crater pictured in the upper right of this image appears to be filled with smooth plains material, perhaps volcanic in nature. This crater was subsequently disrupted by the formation of a prominent scarp (cliff), the surface expression of a major crustal fault system, that runs alongside part of its southern rim and may have led to the uplift seen across a portion of the crater's floor. A smaller crater in the upper left of the image has also been cut by the scarp, showing that the fault beneath the scarp was active after both of these craters had formed. The MESSENGER team is working to combine inferences about the timing of events gained from this image with similar information from the hundreds of other images acquired by MESSENGER to extend and refine the geological history of Mercury previously defined on the basis only of Mariner 10 images. This MESSENGER image was taken from a distance of about 18,000 kilometers (11,000 miles) from the surface of Mercury, at 20:03 UTC, about 58 minutes after the closest approach point of the flyby. The region shown is about 500 kilometers (300 miles) across, and craters as small as 1 kilometer (0.6 mile) can be seen in this image. MESSENGER Views Mercury's Horizon As the MESSENGER spacecraft drew closer to Mercury for its historic first flyby, the spacecraft's Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) acquired an image mosaic of the sunlit portion of the planet. This image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=122 is one of those mosaic frames and was acquired on January 14, 2008, 18:10 UTC, when the spacecraft was about 18,000 kilometers (11,000 miles) from the surface of Mercury, about 55 minutes before MESSENGER's closest approach to the planet. The image shows a variety of surface textures, including smooth plains at the center of the image, many impact craters (some with central peaks), and rough material that appears to have been ejected from the large crater to the lower right. This large 200-kilometer-wide (about 120 miles) crater was seen in less detail by Mariner 10 more than three decades ago and was named Sholem Aleichem for the Yiddish writer. In this MESSENGER image, it can be seen that the plains deposits filling the crater's interior have been deformed by linear ridges. The shadowed area on the right of the image is the day-night boundary, known as the terminator. Altogether, MESSENGER acquired over 1200 images of Mercury, which the science team members are now examining in detail to learn about the history and evolution of the innermost planet. Additional information and features from MESSENGER's first flyby of Mercury will be available online at http://messenger.jhuapl.edu/mer_flyby1.html. Following the flyby, be sure to check for the latest released images and science results! MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery -class mission for NASA. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteor Shower Origin Traced To 1490 Event
http://space.newscientist.com/article/dn13152-meteors-mysterious-origin-traced-to-1490-event.html Meteors' mysterious origin traced to 1490 event Stephen Battersby New Scientist 07 January 2008 Last week's Quadrantid meteor shower was probably debris from a deep-space explosion that went off in the late 15th century, new observations reveal. The meteors, which return every January, were observed more closely than ever before when a group of 14 astronomers tracked them for nine hours on a flight from California, US, to the North Pole. They found that the shower peaked at around 0200 GMT on Friday, matching a prediction made by Peter Jenniskens of NASA. He based his prediction on the theory that the shower originated in 1490, when observers in China, Japan and Korea saw a comet following a path similar to that of the Quadrantids. Apparently a sudden event caused the dormant comet to flare up - like Comet Holmes in October 2007 - leaving behind a stream of debris. Jenniskens calculated that such a young stream should be narrow, and thus easily deflected by Jupiter's gravity. That would make it arrive a few hours earlier than if it were an older, more diffuse stream. Friday's observations confirm the story. A closer analysis of the new data might also give astronomers some clues about what caused the outburst. The 1490 event left behind at least one larger remnant, a near-Earth asteroid called 2003 EH1. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER's Mercury Flyby Science Data Now Safely on Earth
http://messenger.jhuapl.edu/news_room/status_report_01_18_08.html MESSENGER Mission News January 18, 2008 MESSENGER's Mercury Flyby Science Data Now Safely on Earth A day after its successful flyby of Mercury, the MESSENGER spacecraft turned toward Earth on Tuesday and began downloading the 500 megabytes of data that had been stored on the solid-state recorder during the encounter. All of those data, including 1,213 images from the Mercury Dual Imaging System (MDIS) cameras, have now been received by the Science Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. Preliminary analysis of these data by the MESSENGER Science Team has confirmed that all seven MESSENGER instruments are healthy and operated as planned during the flyby. As MESSENGER flew by the planet, it missed its targeted aim point by only 8.25 kilometers (5.12 miles), affording the critical gravity assist needed to continue on a course to become - in 2011 - the first spacecraft ever to orbit Mercury. During this first encounter, the payload successfully conducted a carefully orchestrated sequence of observations designed to take full advantage of the geometry of the flyby trajectory and to optimize the science return from each instrument. In addition to images of the previously unseen portion of the planet's surface, measurements were made that will contribute to the characterization of all aspects of Mercury and its environment, from its metallic core to the far reaches of its magnetosphere. We have one excited Science Team, says MESSENGER Project Manager, Peter D. Bedini, of APL, and their enthusiasm is contagious. The analysis of these data is just beginning, but there are already indications that new discoveries are at hand. Two New Images from MESSENGER Team Reveal Overview of Mercury and the Planet's Cratering History Overview of Mercury as MESSENGER Approached As MESSENGER neared Mercury on January 14, 2008, the spacecraft's Wide Angle Camera on the Mercury Dual Imaging System (MDIS) took images of the planet through each of its 11 filters. This image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=123 of the planet's full crescent was taken using the seventh filter, in light near the far-red end of the visible spectrum (750 nm). The image shows portions of Mercury previously seen by Mariner 10, but when Mariner 10 flew by the planet at each of its encounters the Sun was nearly overhead. For this MESSENGER flyby, in contrast, the Sun is shining obliquely on regions near the day/night boundary (called the terminator) on the right-hand side of the crescent, revealing the surface topography in sharp relief. This image illustrates how MESSENGER, during its future flybys and subsequent orbital mission, will teach us much about the portion of Mercury already imaged by Mariner 10, and not just because of its superior camera and close proximity to the planet. The solar lighting geometry makes an enormous difference. This picture provides a global context for the MDIS Narrow Angle Camera (NAC) images taken while MESSENGER was inbound. For example, the NAC image of the crater Vivaldi, released earlier this week http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1gallery_id=2image_id=118, would fit as a small patch on the terminator just above the center of the crescent. The already released image that includes the crater Sholem Aleichem http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1gallery_id=2image_id=122 shows a part of Mercury near the top of the crescent. More NAC images of the incoming crescent will be released in the future. This image was taken about 80 minutes before closest approach from a distance of about 27,000 kilometers (17,000 miles) and shows features as small as 10 kilometers (6 miles). Mercury's Complex Cratering History On January 14, 2008, MESSENGER observed about half of the hemisphere not seen by Mariner 10. These images http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=124, mosaicked together by the MESSENGER team, were taken by the Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (MDIS) instrument, about 20 minutes after MESSENGER's closest approach to Mercury (2:04 pm EST), when the spacecraft was at a distance of about 5,000 kilometers (about 3100 miles). The image shows features as small as 400 meters (0.25 miles) in size and is about 370 kilometers (230 miles) across. The image shows part of a large, fresh crater with secondary crater chains located near Mercury's equator on the side of the planet newly imaged by MESSENGER. Large, flat-floored craters often have terraced rims from post-impact collapse of their newly formed walls. The hundreds of secondary impactors that are excavated from the
[meteorite-list] Spaceguard UK Campaign for NEO Telescope
http://news.bbc.co.uk/1/hi/wales/mid/7193928.stm Asteroid telescope's fitting bill BBC News January 17, 2008 An observatory which monitors the potential threat to earth from asteroids has launched a campaign to raise money to install a new telescope. The Spaceguard Centre in Knighton, Powys, has been offered the telescope free of charge by the Institute of Astronomy in Cambridge. It would mean the centre could hunt for near earth objects as well as tracking them once they have been discovered. The cost to install and house the device has been estimated at £54,000. Known as a Schmidt camera, it has a wide field of view and takes photographs of the sky, said Jay Tate, who runs the centre. Mr Tate said images were compared to see what had moved and potential comets or asteroids could then be identified. He explained why the telescope had been offered to the centre. They can't use it in Cambridge anymore because of the light pollution, he said. This part of Wales has very dark skies so that wouldn't be a problem. Nasa searches for near earth objects and it funds six telescopes in the US and two in Italy and Australia, but no-one else is doing this sort of work in the UK. It would mean we could search for objects as well as tracking them once they have been identified. The Spaceguard Centre has a robotic telescope which is able to track asteroids and it also has an observatory which attracts school parties and tourists. Mr Tate added that no funding was available from the Welsh Assembly Government, the UK government or the National Lottery to help pay towards installing the new telescope. I am now turning my attention to private sponsorship, he said. Knighton's county councillor Ken Harris said the telescope would be a unique tourist attraction. It would be great if someone or an organisation could help the Spaceguard Centre fund this expansion, he added. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Monnig Meteorite Gallery in Texas Receive Large Slice of Mundrabilla Meteorite
http://media.www.tcudailyskiff.com/media/storage/paper792/news/2008/01/16/News/Monnig.Meteorite.Gallery.Receives.A.Slice.Of.Mundrabilla-3153001.shtml Monnig Meteorite Gallery receives a slice of Mundrabilla Daily Skiff January 16, 2008 The largest iron meteorite slice in the country is coming to Monnig Meteorite Gallery http://www.monnigmuseum.tcu.edu/. The 45-ton meteorite, Mundrabilla, is one of seven slices cut by a dealer in Frankfurt, Germany, and is named after the town in western Australia where it was found, curator Arthur Ehlmann said. The Mundrabilla slice, which measures about 3 feet wide and 2 feet long , is the only slice that will be displayed in the United States, Ehlmann said. Two slices will be returned to Australia, and the other four will be displayed in museums around Europe, Ehlmann said. I think that it is one of the most exquisite pieces we have in the collection, said Teresa Moss, director of the gallery. It's one of my favorites. Ehlmann said he paid nothing for the slice. I had something he wanted, and he had something I wanted, Ehlmann said. The dealer chose 15 duplicate meteorites from the collection to trade for the slice, Ehlmann said. The staff said the slice will join the permanent collection and hope it will be on display within a few weeks. The Monnig Meteorite Gallery http://www.monnigmuseum.tcu.edu/, located in the Sid Richardson Building http://www.maps.tcu.edu/4d.asp, opened its doors to the public in 2003, according to its Web site. Moss said the gallery is a popular field trip site for many local schools and serves as a lab for geology, physics and environment sciences. Moss said she hopes TCU students from all fields would come visit the museum to see the Mundrabilla slice, as well as the rest of the collection. There is not much else like it, Moss said. Come by and touch a piece of the core of a meteorite. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images: January 14-18, 2008
MARS ODYSSEY THEMIS IMAGES January 14-18, 2008 o End of Summer (Released 14 January 2008) http://themis.asu.edu/zoom-20080114a o Reynolds Crater (Released 15 January 2008) http://themis.asu.edu/zoom-20080115a o Russell Crater (Released 16 January 2008) http://themis.asu.edu/zoom-20080116a o Wirtz Crater (Released 17 January 2008) http://themis.asu.edu/zoom-20080118a o Hellas Dunes (Released 18 January 2008) http://themis.asu.edu/zoom-20080114a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Near-Earth Asteroid 2007 TU24 to Pass Close To Past Earth on Jan. 29 - Should be Observable with Modest Sized Telescopes
http://neo.jpl.nasa.gov/news/news157.html Near-Earth Asteroid 2007 TU24 to Pass Close To Past Earth on Jan. 29 - Should be Observable with Modest Sized Telescopes Don Yeomans NASA/JPL Near-Earth Object Program Office January 22, 2008 Asteroid 2007 TU24, discovered by the Catalina Sky Survey on October 11, 2007 will closely approach the Earth to within 1.4 lunar distances (334,000 miles) on 2008 Jan. 29 08:33 UT. This object, between 150 and 600 meters in diameter, will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before quickly becoming fainter as it moves further from Earth. For a brief time the asteroid will be observable in dark and clear skies with amateur telescopes of 3 inch apertures or larger. For an interactive illustration of this object's orbit see: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007+TU24orb=1 The illustration below is courtesy of amateur astronomer Dr. Dale Ireland from Silverdale, WA. The illustration shows the asteroid's track on the sky for 3 days near the time of the close Earth approach as seen from the city of Philadelphia. Since the object's parallax will be a significant fraction of a degree, observers are encouraged to use our on-line Horizons ephemeris generation service for their specific locations. These personalized ephemeris tables can be generated at: http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1body_group=sbsstr=2007%20TU24 [Illustration] Given the estimated number of near-Earth asteroids of this size (about 7,000 discovered and undiscovered objects), an object of this size would be expected to pass this close to Earth, on average, about every 5 years or so. The average interval between actual Earth impacts for an object of this size would be about 37,000 years. For the January 29th encounter, near Earth asteroid 2007 TU24 has no chance of hitting, or affecting, Earth. 2007 TU24 will be the closest currently known approach by a potentially hazardous asteroid of this size or larger until 2027. Plans have been made for the Goldstone planetary radar to observe this object Jan 23-24 and for the Arecibo radar to observe it Jan 27-28 and then Feb 1-4. High resolution radar imaging is expected, which may permit later 3-D shape reconstruction. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Latest MESSENGER Images Show Fascinating Views of Mercury's Surface
http://messenger.jhuapl.edu/news_room/status_report_01_20_08.html MESSENGER Mission News January 20, 2008 Latest MESSENGER Images Show Fascinating Views of Mercury's Surface MESSENGER Views an Intriguing Crater MESSENGER's Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) acquired this view http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=127 of Mercury's surface illuminated obliquely from the right by the Sun. The unnamed crater (52 kilometers, or 31 miles, in diameter) in the center of the image displays a telephone-shaped collapse feature on its floor. Such a collapse feature, not seen on the floors of other craters in this image, could reflect past volcanic activity at and just below the surface of this particular crater. MESSENGER team members are examining closely the more than 1,200 images returned from this flyby for other surface features that can provide clues to the geological history of the innermost planet. The crater is located in the southern hemisphere of Mercury, on the side that was not viewed by Mariner 10 during any of its three flybys in 1974 and 1975. This scene was imaged while MESSENGER was departing from Mercury from a distance of about 19,300 kilometers (12,000 miles), about one hour after the spacecraft's closest encounter with Mercury. The image is of a region approximately 236 kilometers (147 miles) across, and craters as small as 1.6 kilometers (1 mile) can be seen. Ridges and Cliffs on Mercury's Surface A complex history of geological evolution is recorded in this frame http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=128 from the Narrow Angle Camera (NAC), part of the MDIS instrument, taken during MESSENGER's close flyby of Mercury on January 14, 2008. Part of an old, large crater occupies most of the lower left portion of the frame. An arrangement of ridges and cliffs in the shape of a Y crosses the crater's floor. The shadows defining the ridges are cast on the floor of the crater by the Sun shining from the right, indicating a descending stair-step of plains. The main, right-hand branch of the Y crosses the crater floor, the crater rim, and continues off the top edge of the picture; it appears to be a classic lobate scarp (irregularly shaped cliff) common in all areas of Mercury imaged so far. These lobate scarps were formed during a period when Mercury's crust was contracting as the planet cooled. In contrast, the branch of the Y to the left ends at the crater rim and is restricted to the floor of the crater. Both it and the lighter-colored ridge that extends downward from it resemble wrinkle ridges that are common on the large volcanic plains, or maria, on the Moon. The MESSENGER science team is studying what features like these reveal about the interior cooling history of Mercury. Ghostly remnants of a few craters are seen on the right side of this image, possibly indicating that once-pristine, bowl-shaped craters (like those on the large crater's floor) have been subsequently flooded by volcanism or some other plains-forming process. This image was taken 18 minutes after close approach, when MESSENGER was about 5,000 kilometers (about 3,000 miles) away from Mercury. The image is about 200 kilometers (about 125 miles) across, and features as small as about 400 meters (about 400 yards) can be resolved. Additional information and features from MESSENGER's first flyby of Mercury are online at http://messenger.jhuapl.edu/mer_flyby1.html. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery -class mission for NASA. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER: Mercury in Color!
http://messenger.jhuapl.edu/news_room/status_report_01_22_08.html MESSENGER Mission News January 22, 2008 Mercury in Color! One week ago, the MESSENGER spacecraft transmitted to Earth the first high-resolution image of Mercury by a spacecraft in over 30 years since the three Mercury flybys of Mariner 10 in 1974 and 1975. MESSENGER's Wide Angle Camera (WAC), part of the Mercury Dual Imaging System (MDIS), is equipped with 11 narrow-band color filters, in contrast to the two visible-light filters and one ultraviolet filter that were on Mariner 10's vidicon camera. By combining images taken through different filters in the visible and infrared, the MESSENGER data allow Mercury to be seen in a variety of high-resolution color views not previously possible. MESSENGER's eyes can see far beyond the color range of the human eye, and the colors seen in the accompanying image are somewhat different from what a human would see. This color image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=132 was generated by combining three separate images taken through WAC filters sensitive to light in different wavelengths; filters that transmit light with wavelengths of 1000, 700, and 430 nanometers (infrared, far red, and violet, respectively) were placed in the red, green, and blue channels, respectively, to create this image. The human eye is sensitive across only the wavelength range 400 to 700 nanometers. Creating a false-color image in this way accentuates color differences on Mercury's surface that cannot be seen in the single-filter, black-and-white images released last week http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1gallery_id=2image_id=123. This visible-infrared image shows an incoming view of Mercury, about 80 minutes before MESSENGER's closest pass of the planet on January 14, 2008, from a distance of about 27,000 kilometers (17,000 miles). Image sequences acquired through the 11 different MDIS filters are being used to distinguish subtle color variations indicative of different rock types. By analyzing color differences across all 11 filters, the MESSENGER team is investigating the variety of mineral and rock types present on Mercury's surface. Such information will be key to addressing fundamental questions about how Mercury formed and evolved. Mercury has a diameter of about 4,880 kilometers (3,030 miles), and the smallest feature visible in this color image is about 10 kilometers (6 miles) in size. First MESSENGER Spectrum of Mercury During its flyby of Mercury, the MESSENGER spacecraft acquired the first high-resolution spectra of the planet's surface in ultraviolet, visible, and near-infrared light. The image on the left shows a portion of the ground-track along which the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument accumulated over 650 observations of the surface. The depicted area is about 300 kilometers (190 miles) across. The white track covers about 60 of the MASCS footprints or spectral snapshots. The red area highlights about 20 footprints averaged to make the example spectrum on the right, showing the relative amount of sunlight reflected from the surface at wavelengths from the ultraviolet to the visible (rainbow) to the infrared. The observations were taken on January 14, 2008, beginning as the spectrometer's field of view crossed into the day-lit side of the planet at a distance of about 1,900 kilometers (about 1,200 miles), and continuing until the field of view left the planet at a distance of about 8,500 kilometers (about 5,300 miles) from Mercury. Mercury is about 4880 kilometers (about 3030 miles) in diameter, and the footprints shown here are about 1 by 5 kilometers (0.6 by 3.4 miles). The Mercury spectrum shows the degree to which different wavelengths of sunlight are absorbed or reflected by its surface materials. Dips in the spectrum indicate where sunlight shining on the surface is partially absorbed. The absorption bands' sizes and colors are diagnostic of the minerals in surface rocks. While Mercury has been observed telescopically from Earth for centuries, and Mariner 10 took images in one ultraviolet and two color filters when it flew by in 1974 and 1975, MESSENGER is the first mission to observe the surface with enough spatial and spectral resolution to determine Mercury's surface composition. Additional information and features from MESSENGER's first flyby of Mercury are online at http://messenger.jhuapl.edu/mer_flyby1.html. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft
[meteorite-list] Seismic Images Show Dinosaur-Killing Meteor Made Bigger Splas
Office of Public Affairs University of Texas at Austin P.O. Box Z Austin, TX 78713 For more information, contact: Marc Airhart, Jackson School of Geosciences 512-471-2241 January 23, 2008 Seismic Images Show Dinosaur-Killing Meteor Made Bigger Splash AUSTIN, Texas -- The most detailed three-dimensional seismic images yet of the Chicxulub crater, a mostly submerged and buried impact crater on the Mexico coast, may modify a theory explaining the extinction of 70 percent of life on Earth 65 million years ago. The Chicxulub crater was formed when an asteroid struck on the coast of the Yucatan Peninsula. Most scientists agree the impact played a major role in the KT Extinction Event that caused the extinction of most life on Earth, including the dinosaurs. According to Sean Gulick, a research scientist at the Institute for Geophysics at The University of Texas at Austin's Jackson School of Geosciences and principal investigator for the project, the new images reveal the asteroid landed in deeper water than previously assumed and therefore released about 6.5 times more water vapor into the atmosphere. The impact site also contained sulfur-rich sediments called evaporites, which would have reacted with water vapor to produce sulfate aerosols. According to Gulick, an increase in the atmospheric concentration of the compounds could have made the impact deadlier in two ways: by altering climate (sulfate aerosols in the upper atmosphere can have a cooling effect) and by generating acid rain (water vapor can help to flush the lower atmosphere of sulfate aerosols, causing acid rain). Earlier studies had suggested both effects might result from the impact, but to a lesser degree. The greater amount of water vapor and consequent potential increase in sulfate aerosols needs to be taken into account for models of extinction mechanisms, says Gulick. The results appear in the February 2008 print edition of the journal Nature Geosciences. An increase in acid rain might help explain why reef and surface dwelling ocean creatures were affected along with large vertebrates on land and in the sea. As it fell on the water, acid rain could have turned the oceans more acidic. There is some evidence that marine organisms more resistant to a range of pH survived while those more sensitive did not. Gulick says the mass extinction event was probably not caused by just one mechanism, but rather a combination of environmental changes acting on different time scales, in different locations. For example, many large land animals might have been baked to death within hours or days of the impact as ejected material fell from the sky, heating the atmosphere and setting off firestorms. More gradual changes in climate and acidity might have had a larger impact in the oceans. Gulick and collaborators originally set out to learn more about the trajectory of the asteroid. They had hoped the crater's structure in the subsurface would hold a tell-tale signature. Instead, the structure seemed to be most strongly shaped by the pre-impact conditions of the target site. We discovered that the shallow structure of the crater was determined much more by what the impact site was like before impact than by the trajectory of the impactor, says Gulick. If scientists can determine the trajectory, it will tell them where to look for the biggest environmental consequences of impact, because most of the hazardous, shock-heated and fast-moving material would have been thrown out of the crater downrange from the impact. Researchers at Imperial College in London are already using computer models to search for possible signatures in impact craters that could indicate trajectory regardless of the initial surface conditions at the impact site. As someone who simulates impact events using computers, this work provides valuable new constraints on both the pre-impact target structure and the final geometry of the cratered crust at Chicxulub, says Gareth Collins, a research fellow at Imperial College. Collaborators on the project included Gail Christeson of the Institute for Geophysics, Penny Barton at the University of Cambridge, Joanna Morgan and Mike Warner at Imperial College, and several graduate students. Note: The paper Importance of pre-impact crustal structure for the asymmetry of the Chicxulub impact crater can be downloaded online, http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo103.html Related Sites: * Institute for Geophysics http://www.ig.utexas.edu/ * Jackson School of Geosciences http://www.jsg.utexas.edu/ * Research at The University of Texas at Austin http://www.utexas.edu/research/ __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER Dances by Matisse
http://messenger.jhuapl.edu/news_room/status_report_01_23_08.html MESSENGER Mission News January 23, 2008 MESSENGER Dances by Matisse As MESSENGER approached Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) snapped this image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=134 of the crater Matisse. Named for the French artist Henri Matisse, the Matisse crater was imaged during the Mariner 10 mission and is about 210 kilometers (130 miles) in diameter. Matisse crater is in the southern hemisphere and can be seen near the terminator of the planet (the line between the sunlit, day side and the dark, night side) in both the color http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=132 and single-filter, black-and-white http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1gallery_id=2image_id=123 images released previously that show an overview of the entire incoming side of Mercury. On Mercury, craters are named for people, now deceased, who have made contributions to the humanities, such as artists, musicians, painters, and authors. The International Astronomical Union (IAU) oversees the official process of naming new craters and other new features discovered on bodies throughout the solar system. Scientists studying and mapping unnamed features can suggest names for consideration by the IAU. The 1,213 images taken by MESSENGER during its first flyby encounter with Mercury cover a large region of Mercury's surface previously unseen by spacecraft, revealing many new craters and other features that will need to be named. Additional information and features from MESSENGER's first flyby of Mercury are online at http://messenger.jhuapl.edu/mer_flyby1.html. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery -class mission for NASA. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Scientists Get First Images of Asteroid 2007 TU24
http://www.jpl.nasa.gov/news/news.cfm?release=2008-014 NASA Scientists Get First Images of Earth Flyby Asteroid Jet Propulsion Laboratory January 25, 2008 Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have obtained the first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the asteroid is somewhat asymmetrical in shape, with a diameter roughly 250 meters (800 feet) in size. Asteroid 2007 TU24 will pass within 1.4 lunar distances, or 538,000 kilometers (334,000 miles), of Earth on Jan. 29 at 12:33 a.m. Pacific time (3:33 a.m. Eastern time). With these first radar observations finished, we can guarantee that next week's 1.4-lunar-distance approach is the closest until at least the end of the next century, said Steve Ostro, JPL astronomer and principal investigator for the project. It is also the asteroid's closest Earth approach for more than 2,000 years. Scientists at NASA's Near-Earth Object Program Office at JPL have determined that there is no possibility of an impact with Earth in the foreseeable future. Asteroid 2007 TU24 was discovered by the NASA-sponsored Catalina Sky Survey on Oct. 11, 2007. The first radar detection of the asteroid was acquired on Jan. 23 using the Goldstone 70-meter (230-foot) antenna. The Goldstone antenna is part of NASA's Deep Space Network Goldstone station in Southern California's Mojave Desert. Goldstone's 70-meter diameter (230-foot) antenna is capable of tracking a spacecraft traveling more than 16 billion kilometers (10 billion miles) from Earth. The surface of the 70-meter reflector must remain accurate within a fraction of the signal wavelength, meaning that the precision across the 3,850-square-meter (41,400-square-foot) surface is maintained within one centimeter (0.4 inch). Ostro and his team plan further radar observations of asteroid 2007 TU24 using the National Science Foundation's Arecibo Observatory in Puerto Rico on Jan. 27-28 and Feb. 1-4. The asteroid will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before quickly becoming fainter as it moves farther from Earth. On that night, the asteroid will be observable in dark and clear skies through amateur telescopes with apertures of at least 7.6 centimeters (three inches). An object with a magnitude of 10.3 is about 50 times fainter than an object just visible to the naked eye in a clear, dark sky. Scientists working with Ostro on the project include Lance Benner and Jon Giorgini of JPL, Mike Nolan of the Arecibo Observatory, and Greg Black of the University of Virginia. NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called Spaceguard, discovers, characterizes and computes trajectories for these objects to determine if any could be potentially hazardous to our planet. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, a national research center operated by Cornell University, Ithaca, N.Y., for the National Science Foundation. JPL is a division of the California Institute of Technology in Pasadena. For more information, visit http://neo.jpl.nasa.gov Media contact: Contact: DC Agle 818-393-9011 Jet Propulsion Laboratory, Pasadena, Calif. [EMAIL PROTECTED] Grey Hautaluoma 202-358-0668 Headquarters, Washington [EMAIL PROTECTED] 2008-014 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Arecibo Astronomers Prepare to Obtain Close Images of Asteroid 2007 TU24
http://www.eurekalert.org/pub_releases/2008-01/cuc-aap012508.php Public release date: 25-Jan-2008 Contact: Blaine Friedlander [EMAIL PROTECTED] 607-254-8093 Cornell University Communications Arecibo astronomers prepare to obtain close images of a near-Earth asteroid ITHACA, N.Y. - The Arecibo Observatory in Arecibo, Puerto Rico will observe a newly discovered asteroid on Jan. 27-28, as the object called 2007 TU24 passes within 1.4 lunar distances, or 334,000 miles, from Earth. The asteroid, estimated at between 150 and 600 meters in diameter - about 500 feet to 1,900 feet, or the size of a football field, at 360 feet, to the size of Chicago's 110-story Sears Tower, at 1,454 feet - was discovered by the University of Arizona's Catalina Sky Survey in October 2007. It poses no threat to Earth, but its near approach gives Arecibo astronomers a golden opportunity to learn more about potentially hazardous near-Earth objects. We don't yet know anything about this asteroid, said Mike Nolan, head of radar astronomy at the Puerto Rico observatory. Such objects pass near Earth with relative frequency, he said - approximately one every five years or so - but it's rare that astronomers have enough advance notice to plan for rigorous observing. Because it's coming so close, we'll get our highest quality imaging, said Nolan. Using Arecibo's powerful radar, which is the most sensitive in the world, researchers will gauge the object's size, observe its speed and measure its spin. Switching then to imaging mode, which will offer resolution to 7.5 meters - three times more precise than NASA's Goldstone telescope, the only other radar telescope in the world - the researchers hope to map the object's surface in detail. The Robert C. Byrd Green Bank Telescope, Green Bank, W.Va., will receive Arecibo's echo from the asteroid and transmit its data back to Arecibo. TU24 is one of an estimated 7,000 near-Earth objects, its size or larger - most have never been closely studied. We have good images of a couple dozen objects like this, and for about one in 10, we see something we've never seen before, said Nolan. We really haven't sampled the population enough to know what's out there. Arecibo's radar is vital for continuing to classify and understand such objects, said Cornell University assistant professor of astronomy Jean-Luc Margot. Arecibo does a fantastic job at getting images, discovering the shape, spin and reflection properties of such an object . . . all these things that are important to know.' The telescope will be trained on TU24 Jan. 27-28 and again Feb. 1-4. Goldstone's planetary radar observed it Jan. 23-24. ### Steven Ostro, astronomer at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., is principal investigator for the project; also contributing are Lance Benner and Jon Giorgini at JPL and Greg Black of the University of Virginia. Their research is funded by NASA. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, a national research center operated by Cornell for the National Science Foundation. The Green Bank Telescope is operated by National Radio Astronomy Observatory for the National Science Foundation. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER: Counting Mercury's Craters
http://messenger.jhuapl.edu/news_room/status_report_01_24_08.html MESSENGER Mission News January 24, 2008 Counting Mercury's Craters On January 14, 2008, MESSENGER flew by Mercury and snapped images of a large portion of the surface that had not been previously seen by spacecraft. Ever since the first images were received back on Earth one day later, January 15, MESSENGER team members have been closely examining and studying this new terrain with great interest and excitement. One of many investigations underway includes identifying and measuring the impact craters on these previously unseen regions. The density of craters on the surface of a planet can be used to indicate the relative age of different places on the surface; the more craters the surface has accumulated, the older the surface. By counting craters on different areas of Mercury's surface, a relative geologic history of the planet can be constructed, indicating which surfaces formed first and which formed later. However, this process is also time consuming; Mercury has a lot of craters! This image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=136 shows just a portion (276 kilometers, or 172 miles, wide) of one frame taken with the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS). In this image alone, 763 craters have been identified and measured (shown in green) along with 189 hills (shown in yellow). Altogether, 491 frames were taken by the NAC to create high-resolution mosaics of Mercury's surface. Of course, simply counting the craters is not enough. Each crater has to be measured and classified to fully interpret the differences in crater density. Many small craters form as secondaries, as clumps of material ejected from a primary crater re-impact the surface in the regions surrounding the primary. In order to learn about the history of asteroid and comet impacts on Mercury, scientists have to distinguish between the primary and secondary craters. Once many more craters are measured, MESSENGER researchers will have new insights into the geological history of Mercury. Additional information and features from this first flyby will be available online at http://messenger.jhuapl.edu/mer_flyby1.html, so check back frequently. Following the flyby, be sure to check for the latest released images and science results! MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery -class mission for NASA. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - January 24, 2008
MARS RECONNAISSANCE ORBITER HIRISE IMAGES January 24, 2008 o Southern Dunes and Spiders http://hirise.lpl.arizona.edu/PSP_006538_1035 o Layered Sediments in Terby Crater http://hirise.lpl.arizona.edu/PSP_006475_1525 o Splotches and Channels Near Sisyphi Montes http://hirise.lpl.arizona.edu/PSP_005424_1075 o Polar Pit Gullies http://hirise.lpl.arizona.edu/PSP_005410_1115 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Asteroid 2007 TU24 to Make Rare Close Flyby of Earth January 29
http://www.jpl.nasa.gov/news/news.cfm?release=2008-012 Asteroid to Make Rare Close Flyby of Earth January 29 Jet Propulsion Laboratory January 24, 2008 Scientists are monitoring the orbit of asteroid 2007 TU24. The asteroid, believed to be between 150 meters (500 feet) and 610 meters (2,000 feet) in size, is expected to fly past Earth on Jan. 29, with its closest distance being about 537,500 kilometers (334,000 miles) at 12:33 a.m. Pacific time (3:33 a.m. Eastern time). It should be observable that night by amateur astronomers with modest-sized telescopes. Asteroid 2007 TU24 was discovered by the NASA-sponsored Catalina Sky Survey on Oct. 11, 2007. Scientists at NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif., have determined that there is no possibility of an impact with Earth in the foreseeable future. This will be the closest approach by a known asteroid of this size or larger until 2027, said Don Yeomans, manager of the Near Earth Object Program Office at JPL. As its closest approach is about one-and-a-half times the distance of Earth to the moon, there is no reason for concern. On the contrary, Mother Nature is providing us an excellent opportunity to perform scientific observations. Asteroid 2007 TU24 will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before quickly becoming fainter as it moves farther from Earth. On that night, the asteroid will be observable in dark and clear skies through amateur telescopes with apertures of at least 7.6 centimeters (3 inches). An object with a magnitude of 10.3 is about 50 times fainter than an object just visible to the naked eye in a clear, dark sky. NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called Spaceguard, discovers, characterizes and computes trajectories for these objects to determine if any could be potentially hazardous to our planet. For more information, visit http://neo.jpl.nasa.gov. DC Agle 818-393-9011 Jet Propulsion Laboratory, Pasadena, Calif. [EMAIL PROTECTED] Grey Hautaluoma 202-358-0668 Headquarters, Washington [EMAIL PROTECTED] 2008-012 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Stardust Comet Dust Resembles Asteroid Materials
https://publicaffairs.llnl.gov/news/news_releases/2008/NR-08-01-05.html Lawrence Livermore National Laboratory News Release Contact: Anne M. Stark Phone: (925) 422-9799 E-mail: [EMAIL PROTECTED] FOR IMMEDIATE RELEASE January 24, 2008 NR-08-01-05 Stardust comet dust resembles asteroid materials LIVERMORE, Calif. - Contrary to expectations for a small icy body, much of the comet dust returned by the Stardust mission formed very close to the young sun and was altered from the solar system's early materials. When the Stardust mission returned to Earth with samples from the comet Wild 2 in 2006, scientists knew the material would provide new clues about the formation of our solar system, but they didn't know exactly how. New research by scientists at Lawrence Livermore National Laboratory and collaborators reveals that, in addition to containing material that formed very close to the young sun, the dust from Wild 2 also is missing ingredients that would be expected in comet dust. Surprisingly, the Wild 2 comet sample better resembles a meteorite from the asteroid belt rather than an ancient, unaltered comet. Comets are expected to contain large amounts of the most primitive material in the solar system, a treasure trove of stardust from other stars and other ancient materials. But in the case of Wild 2, that simply is not the case. By comparing the Stardust samples to cometary interplanetary dust particles (CP IDPs), the team found that two silicate materials normally found in cometary IDPs, together with other primitive materials including presolar stardust grains from other stars, have not been found in the abundances that might be expected in a Kuiper Belt comet like Wild 2. The high-speed capture of the Stardust particles may be partly responsible; but extra refractory components that formed in the inner solar nebula within a few astronomical units of the sun, indicate that the Stardust material resembles chondritic meteorites from the asteroid belt. The material is a lot less primitive and more altered than materials we have gathered through high altitude capture in our own stratosphere from a variety of comets, said LLNL's Hope Ishii, lead author of the research that appears in the Jan. 25 edition of the journal, Science. As a whole, the samples look more asteroidal than cometary. Because of its tail formed by vaporizing ices, Wild 2 is, by definition, a comet. It's a reminder that we can't make black and white distinctions between asteroids and comets, Ishii said. There is a continuum between them. The surprising findings contradict researchers' initial expectations for a comet that spent most of its life orbiting in the Kuiper Belt, beyond Neptune. In 1974, Wild 2 had a close encounter with Jupiter that placed it into its current orbit much closer to Earth. Comets formed beyond the so-called frost line where water and other volatiles existed as ices. Because of their setting far from the sun, they have been viewed as a virtual freezer, preserving the original preliminary ingredients of the solar system's formation 4.6 billion years ago. The Stardust spacecraft traveled a total of seven years to reach Wild 2 and returned to Earth in January 2006 with a cargo of tiny particles for scientist to analyze. This is one of the first studies to closely compare Stardust particles to CP IDPs. This class of IDPs is believed to contain the most primitive and unaltered fraction of the primordial material from which our planets and other solar system objects formed. They are highly enriched in isotopically anomalous organic and inorganic outer solar nebula materials inherited - through the presolar molecular cloud - from dust produced around other stars. IDPs are gathered in the stratosphere by high altitude airplanes (ER-2s and WB-57s) that are typically more than 50 years old. The Livermore team specifically searched for two silicate materials in Stardust that are believed to be unique to cometary IDPs: amorphous silicates known as GEMS (glass with embedded metal and sulfides); and sliver-like whiskers of the crystalline silicate enstatite (a rock-forming mineral). Surprisingly, the team found only a single enstatite whisker in the Stardust samples, and it had the wrong crystallographic orientation - a form typical of terrestrial and asteroidal enstatite. Objects similar to GEMS were found, but Ishii and the team showed they were actually created during the high speed 6-kilometer per second impact of Wild 2 comet dust with the Stardust spacecraft's collector by making similar material in the laboratory. In analyzing the Stardust material, Ishii's team used Livermore's SuperSTEM (scanning transmission electron microscope). Ishii said future analyses should focus on larger-grained materials, so-called micro-rocks, which suffered less alteration. The material found in primitive objects just wasn't there in the samples, said John Bradley, another LLNL author. I think
[meteorite-list] Mars Odyssey THEMIS Images: January 21-25, 2008
MARS ODYSSEY THEMIS IMAGES January 21-25, 2008 o Aonia Terra Dunes (Released 21 January 2008) http://themis.asu.edu/zoom-20080121a o Copernicus Dunes (Released 22 January 2008) http://themis.asu.edu/zoom-20080122a o Dust Devil Tracks (Released 23 January 2008) http://themis.asu.edu/zoom-20080123a o Gullies (Released 24 January 2008) http://themis.asu.edu/zoom-20080124a o Gullies (Released 25 January 2008) http://themis.asu.edu/zoom-20080125a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] New Horizons: A Hi-Def Peek at Pluto
http://pluto.jhuapl.edu/news_center/news/012408.htm New Horizons: NASA's Pluto-Kuiper Belt Mission January 24, 2008 A Hi-Def Peek at Pluto New Horizons made its first detection of Pluto using the high-resolution mode of its Long Range Reconnaissance Imager (LORRI) during three separate sets of observations in October 2007. LORRI first detected Pluto in September 2006 in its low-resolution format, says New Horizons Principal Investigator Alan Stern, of NASA Headquarters, but this time around we were able to take longer exposures and to detect Pluto using a camera resolution that is four times better than before. New Horizons was still too far from Pluto (3.6 billion kilometers, or 2.2 billion miles) for LORRI to resolve any details on Pluto's surface - that won't happen until summer 2014, approximately one year before closest approach. For now the entire Pluto system remains a bright dot to the spacecraft's telescopic camera, though LORRI is expected to start resolving Charon from Pluto - seeing them as separate objects - in summer 2010. During the October 2007 observations, Pluto was located in the constellation Serpens, in a region of the sky dense with background stars. Using LORRI's high-resolution mode allowed us to more easily pick out Pluto in a virtual sea of surrounding stars, says New Horizons Project Scientist Hal Weaver of the Johns Hopkins University Applied Physics Laboratory (APL), which provided the LORRI instrument. Marking another first for New Horizons, LORRI also detected clear variations in Pluto's brightness. Pluto rotates on its axis once every 6.4 days, allowing observers to see different portions of the planet's surface (i.e., different longitudes). From ground-based and Hubble Space Telescope observations scientists have seen repeatable, well-defined differences in Pluto's brightness they believe is caused by variations in frost cover over its surface. New Horizons will determine whether that is indeed the correct explanation when the spacecraft flies by Pluto in July 2015. In the meantime, it's gratifying to see that New Horizons itself now has the capability to track Pluto's brightness variations over the next seven and a half years, and from a slightly different perspective than what we normally see from Earth, Weaver says. [Image] This image demonstrates the first detection of Pluto using LORRI's high-resolution mode, which provides a clear separation between Pluto and numerous nearby background stars. Typically, LORRI's exposure time in hi-res mode is limited to approximately 0.1 seconds, but by using a special pointing mode that allowed an increase in the exposure time to 0.967 seconds, scientists were able to spot Pluto, which is approximately 15,000 times fainter than human eyes can detect. [Image] This montage shows the effects of using different resolutions and exposure times during LORRI observations of Pluto on October 6, 2007. The top left image was taken with LORRI in high-resolution mode using an exposure time of 0.967 seconds. The image to its right had the same exposure time but was taken in LORRI's low-resolution mode with pixels that are four times larger, which makes the stars and Pluto look fatter and, therefore, less distinct. The image to the lower left is another LORRI image taken in low-resolution mode, but with an exposure time that is four seconds longer, which allows us to see deeper and pick up even fainter stars. (Pluto is clearly detected and is circled in each of these LORRI images.) The lower right image is a digitized photographic plate of the same portion of the sky taken in July 1986 by a large telescope in Australia for the Palomar Sky Survey. Pluto is not in this image, but Pluto's location in the October 2007 observations is indicated by the small red circle. This image captures stars that are approximately 40 times fainter than can be seen in the lower left LORRI image and illustrates the richness of the background star field in this region of the sky. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MESSENGER: A Closer Look at the Previously Unseen Side of Mercury
http://messenger.jhuapl.edu/news_room/status_report_01_28_08.html MESSENGER Mission News January 28, 2008 A Closer Look at the Previously Unseen Side of Mercury Two weeks ago, on January 14, 2008, MESSENGER became the first spacecraft to see the side of Mercury shown in this image. The first image transmitted back to Earth following the flyby of Mercury http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=3gallery_id=2image_id=129, and then released to the web within hours, shows the historic first look at the previously unseen side. This image http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2image_id=141preview=Y, taken by the Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS), shows a closer view of much of that territory. Just above and to the left of center of this image is a small crater with a pronounced set of bright rays extending across Mercury's surface away from the crater. Bright rays are commonly made in a crater-forming explosion when an asteroid strikes the surface of an airless body like the Moon or Mercury. But rays fade with time as tiny meteoroids and particles from the solar wind strike the surface and darken the rays. The prominence of these rays implies that the small crater at the center of the ray pattern formed comparatively recently. This image is one in a planned set of 99. Nine different views of Mercury were snapped in this set to create a mosaic pattern with images in three rows and three columns. The WAC is equipped with 11 narrow-band color filters, and each of the nine different views was acquired through all 11 filters. This image was taken in filter 7, which is sensitive to light near the red end of the visible spectrum (750 nm), and shows features as small as about 6 kilometers (4 miles) in size. The MESSENGER team is studying this previously unseen side of Mercury in detail to map and identify new geologic features and to construct the planet's geological history. Additional information and features from this first flyby will be available online at http://messenger.jhuapl.edu/mer_flyby1.html, so check back frequently. Following the flyby, be sure to check for the latest released images and science results! MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery -class mission for NASA. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA to Release Science Results and New Images From Mercury Flyby
Jan. 28, 2008 Dwayne Brown Headquarters, Washington 202-358-1726 [EMAIL PROTECTED] MEDIA ADVISORY: M08-019 NASA TO RELEASE SCIENCE RESULTS AND NEW IMAGES FROM MERCURY FLYBY WASHINGTON - NASA will hold a press conference at 1 p.m. EST on Wednesday, Jan. 30, to announce scientific findings and release never-before-seen images of Mercury. The images were taken during a NASA spacecraft's January flyby of the planet. The briefing will take place in the NASA Headquarters' James E. Webb Auditorium, 300 E Street, S.W., Washington, and will be carried live on NASA Television. NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (Messenger) spacecraft is the first mission sent to orbit the planet closest to our sun. After a journey of more than 2 billion miles, the spacecraft made its first flyby of Mercury on Jan. 14. The spacecraft's cameras and other sophisticated, high-technology instruments collected more than 1,200 images and made other observations. Data included the first up-close measurements of Mercury since the Mariner 10 spacecraft's third and final flyby on March 16, 1975. Participants in the press conference will be: - James Green, director, Planetary Science Division, NASA Headquarters, Washington - Sean Solomon, Mesenger principal investigator; director, Department of Terrestrial Magnetism, Carnegie Institution of Washington - Maria Zuber, Messenger science team member; head, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge - Robert Strom, Messenger science team member; professor emeritus, Lunar and Planetary Laboratory, University of Arizona, Tucson - Louise Prockter, instrument scientist for the Mercury Dual Imaging System, Johns Hopkins University Applied Physics Laboratory, Laurel, Md. Reporters may ask questions from participating NASA locations. The briefing also will be streamed live on NASA's Web site at: http://www.nasa.gov -end- __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Asteroid 2007 TU24 Zooms by Earth
http://www.jpl.nasa.gov/news/news.cfm?release=2008-014a Asteroid Zooms by Earth Jet Propulsion Laboratory January 29, 2008 As expected, Asteroid 2007 TU24 made its closest approach to Earth at 12:33 a.m. today, Jan. 29 (3:33 a.m. Eastern time), and is now headed away from our planet. At its closest point, the asteroid was 554,209 kilometers (344,370 miles) from Earth, or roughly 1.4 times the distance between the moon and Earth. Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif. had tracked the asteroid in advance and determined that there was no possibility of an impact. The rare close approach is providing a bonanza for scientists, who plan to scrutinize images and data gathered in hopes of learning more about our solar system's closest neighbors - near-Earth asteroids. More observations are planned for Feb. 1 through 4 using the Arecibo Observatory in Puerto Rico. The observatory is operated by Cornell University, Ithaca, N.Y., for the National Science Foundation. Media contact: Contact: DC Agle 818-393-9011 Jet Propulsion Laboratory, Pasadena, Calif. [EMAIL PROTECTED] Grey Hautaluoma 202-358-0668 Headquarters, Washington [EMAIL PROTECTED] [Image] This radar image of 2007 TU24 was obtained on January 28, 2008, about 12 hours before the asteroid's 1.4-lunar-distance pass by the Earth. The Arecibo Observatory in Puerto Rico and the Greenbank Telescope in West Virginia were used to take this image. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Surprises Stream Back From Mercury's MESSENGER
The Johns Hopkins University Applied Physics Laboratory Office of Communications and Public Affairs Laurel, Maryland Media Contacts: Paulette Campbell (240) 228-6792 or (443) 778-6792, [EMAIL PROTECTED] Tina McDowell, Carnegie Institution of Washington 202-939-1120, [EMAIL PROTECTED] January 30, 2008 FOR IMMEDIATE RELEASE SURPRISES STREAM BACK FROM MERCURY'S MESSENGER After a journey of more than 2.2 billion miles and three and a half years, NASA's MESSENGER spacecraft made its first flyby of Mercury just after 2 p.m. EST on Jan. 14, 2008. All seven scientific instruments worked flawlessly, producing a stream of surprises that is amazing and delighting the science team. The 1,213 mages conclusively show that the planet is a lot less like the Moon than many previously thought, with features unique to this innermost world. The puzzling magnetosphere appears to be very different from what Mariner 10 discovered and first sampled almost 34 years ago. This flyby allowed us to see a part of the planet never before viewed by spacecraft, and our little craft has returned a gold mine of exciting data, stated Sean Solomon, principal investigator and the director of the Department of Terrestrial Magnetism at the Carnegie Institution of Washington. From the perspectives of spacecraft performance and maneuver accuracy, this encounter was near-perfect, and we are delighted that all of the science data are now on the ground. The science team appreciates that this mission required a complex flight trajectory and a spacecraft that can withstand the intense thermal environment near the Sun. Without the hundreds of engineers and technicians at the Applied Physics Laboratory and all of the partner organizations who designed, assembled, tested, and now operate the spacecraft, we would not have been able to make any of the scientific observations now in hand. MESSENGER has shown that Mercury is even more different from the Moon than we'd thought, said Science Team co-investigator James Head, professor at Brown University and chair of the mission's Geology Discipline Group. The tiny spacecraft discovered a unique feature that the scientists dubbed The Spider. This type of formation has never been seen on Mercury before, and nothing like it has been observed on the Moon. It is in the middle of the Caloris basin and consists of over a hundred narrow, flat-floored troughs (called graben) radiating from a complex central region. The Spider has a crater near its center, but whether that crater is related to the original formation or came later is not clear at this time. Unlike the Moon, Mercury also has huge cliffs or scarps, structures snaking up to hundreds of miles across the planet's face, tracing patterns of fault activity from early in Mercury's -- and the solar system's -- history. The high density and small size of Mercury combine to provide a surface gravity about 38 percent that of Earth and almost exactly the same as that of Mars, which is some 40 percent larger than Mercury in diameter (2.7 times Mercury's volume). Because gravity is stronger on Mercury than on the Moon, impact craters appear very different from lunar craters; material ejected during impact on Mercury falls closer to the rim and many more secondary crater chains are present. We have seen new craters along the terminator on the side of the planet viewed by Mariner 10 where the illumination of the MESSENGER images revealed very subtle features. Technological advances that have been incorporated in MESSENGER are effectively revealing an entirely new planet from what we saw over 30 years ago, said Science Team co-investigator Robert Strom, professor emeritus at the University of Arizona and the only member of both the MESSENGER and Mariner 10 science teams. Now that MESSENGER has shown scientists the full extent of the Caloris basin, its diameter has been revised upward from the Mariner 10 estimate of 800 miles to perhaps as large as 960 miles (about 1,550 kilometers) from rim crest to rim crest. The plains inside the Caloris basin are distinctive and have a higher reflectance -- albedo -- than the exterior plains, the opposite characteristics from many lunar impact basins such as the Imbrium basin on the Moon, yet another new mystery for Mercury. This finding could be the result of several processes -- when the basin was formed by a large impact, deeper material may have been excavated that contributed to impact melt now preserved on the basin floor; alternatively, the basin interior may have been volcanically resurfaced by magma produced deep in Mercury's crust or mantle subsequent to the impact. The science team is eagerly exploring the possibilities. The magnetosphere of Mercury during the MESSENGER flyby appears to be very different from what Mariner 10 saw. MESSENGER found that the planet's magnetic field was generally quiet but showed several signatures indicating
[meteorite-list] MRO HiRISE Images - January 30, 2008
MARS RECONNAISSANCE ORBITER HIRISE IMAGES January 30, 2008 o Possible Salt Deposits in Noachis Terra http://hirise.lpl.arizona.edu/PSP_006649_1615 o Potential Landing Site in Nili Fossae http://hirise.lpl.arizona.edu/PSP_006633_2010 o Clay Minerals in the Northwestern Bosporos Montes http://hirise.lpl.arizona.edu/PSP_006625_1405 o Potential Landing Site Near Mawrth Vallis http://hirise.lpl.arizona.edu/PSP_006610_2035 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images: January 28 - February 1, 2008
MARS ODYSSEY THEMIS IMAGES January 28 - February 1, 2008 o Lava Flows (Released 28 January 2008) http://themis.asu.edu/zoom-20080128a o Hills and Flows (Released 29 January 2008) http://themis.asu.edu/zoom-20080129a o Meridiani (Released 30 January 2008) http://themis.asu.edu/zoom-20080130a o Landslides (Released 31 January 2008) http://themis.asu.edu/zoom-20080131a o Landslides (Released 01 February 2008) http://themis.asu.edu/zoom-20080201a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Exploration Rover Update - February 6, 2008
http://marsrovers.jpl.nasa.gov/mission/status.html#opportunity OPPORTUNITY UPDATE: Still Grinding After All These Years - sol 1389-1395, Feb 06, 2008: With only about a month remaining before Opportunity's fourth anniversary (in Earth years) of Mars exploration, NASA's robotic geologist is still grinding into the surface of rocks to unlock the secrets of their interior chemistry. Meanwhile, fall arrived in the southern hemisphere of Mars on Dec. 9, 2007, Opportunity's 1,378th Martian day, or sol, of exploration of the Red Planet. Ten days later, Earth made its closest approach to Mars, coming within 88 million kilometers (54.8 million miles). Opportunity used the rock abrasion tool to bore a shallow hole into a rock target known as Lyell_1 and then spent about 70 hours integrating data about iron minerals inside the rock using the Moessbauer spectrometer. During integration with the Moessbauer spectrometer, the rover adds measurements in a running total, sort of like exposing film. A longer exposure builds up the light areas, improves contrast, and results in a clearer, more distinct image, whereas a shorter exposure produces an image that is somewhat underexposed, darker, and less well defined. Similarly, longer integrations with the Moessbauer spectrometer yield more distinct signatures of iron content and the chemical state of the iron. At the end of the Moessbauer campaign, Opportunity re-positioned the robotic arm to take images of the grind hole. The rover's handlers postponed acquiring images until after the holidays. On sol 1395 (Dec. 27, 2007), Opportunity acquired a mosaic of microscopic images of the ground rock surface before placing the alpha-particle X-ray spectrometer on a new rock target known as Lyell_2. The resulting 2-by-2-by-14 mosaic was a collection of microscopic images arranged side-by-side like the four windowpanes in a square window. Within each of the four panes, Opportunity took 14 microscopic images at various distances from the rock surface. Because the microscopic imager is a fixed-focus camera, this process of acquiring images at different heights enables the rover to obtain images with different focal points. Because engineers don't always know where the best focus point will be, they start high, move closer, and finish low. Ideally, the middle pictures will be perfectly focused and higher and lower images will be slightly fuzzy. Usually, the rover takes a stack of five microscopic images. This time, however, Opportunity took one image up high, one image down low, and four images at each of the three intervening heights. The multiple images will allow image processing experts to determine a digital average and cancel out unwanted data, known as noise to engineers. In addition to studies using the Moessbauer and alpha-particle X-ray spectrometers, Opportunity conducted routine atmospheric tests, acquiring so-called Tau measurements of atmospheric dust with the panoramic camera. The rover took additional panoramic camera images of the immediate area using multiple filters. By combining images taken with different filters, engineers can create both true- and false-color views. Following is a typical sol in the life of the Opportunity rover: Each Martian day is divided into blocks of activities separated by naps. The first block, known as the engineering block, begins when sunlight is strongest and temperatures are warmest. This is when the rover performs the bulk of the day's activities, including drives and housekeeping activities such as arm movements. After this, Opportunity takes a nap with no activities to allow the early afternoon sun to recharge the rover batteries. In the late afternoon, the rover wakes up for a communication session with the orbiting Odyssey spacecraft. This period is known as the Odyssey block and involves pre-Odyssey, Odyssey, and post-Odyssey activities. Afterward, the rover naps or goes into a deep sleep. During deep sleep, the rover shuts off power to almost everything on board. The following morning, the rover may wake up autonomously if there is enough solar power -- this time period is called solar array wakeup. During this block, engineers usually schedule one or two small activities, followed by another nap to recharge the batteries. If there isn't enough solar power, the rover omits the solar array wakeup block. Finally, the rover wakes up for the daily X-band communication session with Earth. This is known as the AM block. At this time, the rover generally does imaging activities in parallel with communications. This block ends with a so-called handover from the previous sol's plan to the new sol's plan. Sol-by-sol summary: In addition to morning uplinks directly from Earth via the rover's high-gain antenna, evening downlinks to Earth via the Odyssey orbiter at UHF frequencies, and panoramic camera measurements of atmospheric opacity caused by dust, Opportunity completed the following activities: Sol 1389 (Dec. 20, 2007):
[meteorite-list] Mars Odyssey THEMIS Images: February 4-8, 2008
MARS ODYSSEY THEMIS IMAGES February 4-8, 2008 o Landslide Surface (Released 04 February 2008) http://themis.asu.edu/zoom-20080204a o Candor Chasma (Released 05 February 2008) http://themis.asu.edu/zoom-20080205a o Embayment (Released 06 February 2008) http://themis.asu.edu/zoom-20080206a o Channel to Ridge (Released 07 February 2008) http://themis.asu.edu/zoom-20080207a o Crater Delta (Released 08 February 2008) http://themis.asu.edu/zoom-20080208a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] MRO HiRISE Images - February 7, 2008
MARS RECONNAISSANCE ORBITER HIRISE IMAGES February 7, 2008 o Small Cones North of Olympus Mons http://hirise.lpl.arizona.edu/PSP_006667_2150 o Textured Surface in the Southern Part of Trumpler Crater http://hirise.lpl.arizona.edu/PSP_006734_1180 o Terby Crater http://hirise.lpl.arizona.edu/PSP_006752_1525 o HiRISE Student Image of the Week: Intersection of Hyblaeus and Elysium Chasmata http://hirise.lpl.arizona.edu/PSP_003545_2025 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Dawn Journal - January 31, 2008
http://dawn.jpl.nasa.gov/mission/journal_1_31_08.asp Dawn Journal Dr. Marc Rayman January 31, 2008 Dear Dawnnoisseurs, Now in interplanetary cruise, the Dawn spacecraft is following a much more leisurely pace than the one it maintained during the initial checkout phase of the mission. While its daily schedule is not demanding, as it follows (and changes) its orbit around the Sun, it is separating from Earth at nearly 4 light seconds per day (more than 1.1 million kilometers, or 720 thousand miles, per day). Every 8 hours, the probe recedes from Earth by a distance equal to that between Earth and the moon. The spacecraft has accumulated more than 1000 hours of thrusting with its ion propulsion system. Although far, far longer than the overwhelming majority of spacecraft have operated their propulsion systems, this represents only a small fraction of the total thrusting required to complete its solar system journey. [Note to editors: This milestone may be of significance only to human readers. When translated for those who use different numbering systems or different time systems, it may not yield an interesting result. (For that matter, 1000 hours is not a special number when expressed in seconds, days, or millennia.)] Most of Dawn's time is devoted to thrusting with its ion propulsion system, but each week the spacecraft stops for a communications session with controllers on distant Earth, during which it returns detailed data on the performance of its subsystems throughout the previous week. Reports of voltages and currents, temperatures and pressures, and myriad other parameters allow engineers to determine how well the ship has been doing and how to keep it sailing as smoothly as possible. On January 14 shortly before 10:00 pm PST, a high energy subatomic particle, a cosmic ray, traveled through one of the main panels of the spacecraft and then penetrated one of the electronics units. The energy it carried had been imparted to it through an unidentified cosmic process, and after the particle had traveled across vast distances, that energy was transferred to a small integrated circuit. Such an event is not all that uncommon on spacecraft, and Dawn is designed so that most space radiation does not interfere with its operation. The deposition of energy in this particular component however triggered the electronics to inform the software of a problem. To rectify the situation, other software correctly responded by resetting the computer in that unit. In the last log, we saw that two master computers work together to oversee and control activities on the spacecraft. The computer that was reset in this case was neither of those; it was one of many auxiliary computers with more limited responsibilities. In addition to resetting the computer, software running in the main computer correctly reconfigured systems onboard to safe mode. The spacecraft then awaited instructions from engineers on Earth (or, more accurately, in Dawn mission control on the top floor of JPL's whimsically named building 264). A few hours later, when it was time for the weekly communications session, the Deep Space Network and mission controllers promptly recognized that the spacecraft was in safe mode. As with the safing in November, a small team gathered during the night to begin the diagnosis, and more team members joined after dawn. It did not take long to reach a conclusive explanation based on the error code stored by the software and other data downloaded from the spacecraft. The culprit was a cosmic ray. By the time the detailed analysis of the safing was concluding, mission controllers were already commanding the spacecraft step-by-step out of safe mode, returning it to its normal flight configuration. Within a few days, Dawn was ready to resume work, and before the end of the week was thrusting with its ion propulsion system again. (The effect of having missed some thrusting that week is not significant for the mission.) While Dawn will thrust during most of its interplanetary cruise, the flight plan includes some periods of coasting in addition to the normal weekly communications session. One such period was January 22 - 25. Most of this time was devoted to updating software in the main computer. The main software resides in 4 locations (well, 4 locations on the spacecraft): primary and backup copies in the primary main computer and primary and backup copies in the backup main computer. Three copies of flight software 7.0 were installed on the spacecraft in November. As reported in the last log, ournal_12_17_07.asp#backup, the primary main computer was scheduled to receive its backup copy during this break in thrusting. While it had been planned before launch to transmit 7.0 to the spacecraft in November, after the software was finalized, the need for one additional change was recognized. For technical reasons it was not necessary to change all the stored copies; rather, it was sufficient to modify (or patch) only
[meteorite-list] MRO HiRISE Images - February 14, 2008
MARS RECONNAISSANCE ORBITER HIRISE IMAGES February 14, 2008 o Layers on Floor of Trough in Noctis Labyrinthis http://hirise.lpl.arizona.edu/PSP_006679_1680 o Dunes with Unusual Gully http://hirise.lpl.arizona.edu/PSP_006648_1300 o Light-toned Layers in Eos Chaos http://hirise.lpl.arizona.edu/PSP_005385_1640 o Inverted Channels North of Juventae Chasma http://hirise.lpl.arizona.edu/PSP_006770_1760 All of the HiRISE images are archived here: 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. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Odyssey THEMIS Images: February 11-15, 2008
MARS ODYSSEY THEMIS IMAGES February 11-15, 2008 o Wind Action (Released 11 February 2008) http://themis.asu.edu/zoom-20080211a o Sand and Rock (Released 12 February 2008) http://themis.asu.edu/zoom-20080212a o Argyre Dunes (Released 13 February 2008) http://themis.asu.edu/zoom-20080213a o Dark Slope Streaks (Released 14 February 2008) http://themis.asu.edu/zoom-20080214a o Wind Action (Released 15 February 2008) http://themis.asu.edu/zoom-20080215a All of the THEMIS images are archived here: http://themis.asu.edu/latest.html NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in co.oration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Mars Rovers Sharpen Questions About Livable Conditions
http://www.jpl.nasa.gov/news/news.cfm?release=2008-026 Mars Rovers Sharpen Questions About Livable Conditions Jet Propulsion Laboratory February 15, 2008 BOSTON -- Like salt used as a preservative, high concentrations of dissolved minerals in the wet, early-Mars environment known from discoveries by NASA's Opportunity rover may have thwarted any microbes from developing or surviving. Not all water is fit to drink, said Andrew Knoll, a member of the rover science team who is a biologist at Harvard University, Cambridge, Mass. Opportunity and its twin, Spirit, began their fifth year on Mars last month, far surpassing their prime missions of three months. Today, at a meeting of the American Association for the Advancement of Science in Boston, scientists and engineers discussed new observations by the rovers, recent analysis of some earlier discoveries, and perspectives on which lessons from these rovers' successes apply to upcoming missions to Mars. The engineering efforts that have enabled the rovers' longevity have tremendously magnified the science return, said Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the rovers' science payload. All of Spirit's most important findings, such as evidence for hot springs or steam vents, came after the prime mission. Opportunity spent recent months examining a bright band of rocks around the inner wall of a crater. Scientists previously hypothesized this material might preserve a record of the ground surface from just before the impact that excavated the crater. Inspection suggests that, instead, it was at the top of an underground water table, Squyres reported. Experiments with simulated Martian conditions and computer modeling are helping researchers refine earlier assessments of whether the long-ago conditions in the Meridiani area studied by Opportunity would have been hospitable to microbes. Chances look slimmer. At first, we focused on acidity, because the environment would have been very acidic, Knoll said. Now, we also appreciate the high salinity of the water when it left behind the minerals Opportunity found. This tightens the noose on the possibility of life. Conditions may have been more hospitable earlier, with water less briny, but later conditions at Meridiani and elsewhere on the surface of Mars appear to have been less hospitable, Knoll said. Life at the Martian surface would have been very challenging for the last 4 billion years. The best hopes for a story of life on Mars are at environments we haven't studied yet -- older ones, subsurface ones, he said. NASA's current rovers and orbiters at Mars pursue the agency's follow the water theme for Mars exploration. They decipher the roles and fate of water on a planet whose most striking difference from Earth is a scarcity of water. Our next missions, Phoenix and Mars Science Laboratory, mark a transition from water to habitability -- assessing whether sites where there's been water have had conditions suited to life, said Charles Elachi, director of NASA's Jet Propulsion Laboratory, Pasadena, Calif. Where conditions were habitable, later missions may look for evidence of life. Elachi cited the achievements of Spirit and Opportunity. They have worked 16 times longer than planned, driven 20 times farther than planned, and, most important, found diverse geological records of the effects of water in ancient Martian environments, he said. We must not let these successes lull us into thinking this type of exploration is easy. Fifty years into the Space Age, we are still in the golden age of robotic exploration of our solar system, when each mission is unprecedented in some way as we push the limits of what is possible. Each mission presents new challenges. The Phoenix lander, on course to reach Mars on May 25, will assess habitability of a shallow subsurface environment of icy soil farther north than any earlier mission has landed. It revives technology from missions launched before Spirit and Opportunity. The following mission, the Mars Science Laboratory rover, will incorporate many lessons from the current rovers, said that project's manager, Richard Cook of JPL. The next rover will be much bigger to carry the instruments necessary for meeting its goals, but it would be laughable to consider doing Mars Science Laboratory without the experience gained from doing the Mars Exploration Rovers, he said. The Mars Science Laboratory rover will weigh about four times as much as Spirit or Opportunity. There's no way we could use an airbag landing, said JPL's Rob Manning, chief engineer for the future rover. Instead, a rocket-powered hovering stage will lower it to the surface on a tether. Lessons from Spirit and Opportunity will come into play when it starts driving, though. With the current rovers, we've learned we can trust the autonomous navigation technology to a level we never expected, so now we can include that as a capability in our mission design for Mars Science
[meteorite-list] Traces of the Martian Past in the Terby Crater (Mars Express)
http://www.esa.int/SPECIALS/Mars_Express/SEMSEWEMKBF_0.html Traces of the martian past in the Terby crater European Space Agency Mars Epxress 25 January 2008 The High Resolution Stereo Camera (HRSC) on board ESA's Mars Express has returned striking scenes of the Terby crater on Mars. The region is of great scientific interest as it holds information on the role of water in the history of the planet. The image data was obtained on 13 April 2007 during orbit 4199, with a ground resolution of approximately 13 m/pixel. The Sun illuminates the scene from the west (from above in the image). [Terby crater context map] Terby crater lies at approximately 27 degrees south and 74 degrees east, at the northern edge of the Hellas Planitia impact basin in the southern hemisphere of Mars. [Terby crater] The crater, named after the Belgian astronomer Francois J. Terby (1846 â 1911), has a diameter of approximately 170 km. The scene shows a section of a second impact crater in the north. [Terby crater: annotated nadir view, see full caption for details] Eye-catching finger-shaped plateaux extend in the north-south direction. They rise up to 2000 m above the surrounding terrain. The relatively old crater was filled with sediments in the past, which formed plateaux on erosion. [Terby crater, perspective view] The flanks of the plateaux clearly exhibit layering of different-coloured material. Differences in colour usually indicate changes in the composition of the material and such layering is called bedding. Bedding structures are typical of sedimentary rock, which has been deposited either by wind or water. Different rock layers erode differently, forming terraces. [A perspective view of Terby crater] The valleys exhibit gullies, or channels cut in the ground by running liquid, mainly in the northern part of the image. These gullies and the rock-bedding structure indicate that the region has been affected by water. [Terby crater, nadir view] The sediments in this region are interesting to study because they contain information on the role of water in the history of the planet. This is one of the reasons why Terby crater was originally short listed as one of 33 possible landing sites for NASAâs Mars Science Laboratory mission, planned for launch in 2009. [Terby crater, 3D view] The colour scenes have been derived from the three HRSC colour channels and the nadir channel. The perspective views have been calculated from the digital terrain model derived from the HRSC stereo channels. The 3D anaglyph image was calculated from the nadir channel and one stereo channel, stereoscopic glasses are required for viewing. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] First Near-Earth Triple Asteroid Discovered by Arecibo Observatory Astronomers
Press Relations Office Cornell University Ithaca, New York Media Contact: Blaine Friedlander Phone: (607) 254-8093 FOR RELEASE: Feb. 13, 2008 First near-Earth triple asteroid discovered by Arecibo Observatory astronomers -- a mere 7 million miles from Earth ITHACA, N.Y. -- Once considered just your average single asteroid, 2001 SN263 has now been revealed as the first near-Earth triple asteroid ever found. The asteroid -- with three bodies orbiting each other -- was discovered this week by astronomers at the sensitive radar telescope at Cornell University's Arecibo Observatory in Puerto Rico. Cornell University and Arecibo astronomer Michael C. Nolan said he and his colleagues made the discovery when they obtained radar images Feb. 11. The group subsequently took more images to learn that the three objects -- about 7 million miles from Earth -- are rotating around each other. The main, central body is spherical with a diameter of roughly 1.5 miles (2 kilometers), while the larger of the two moons is about half that size. The smallest object is about 1,000 feet across, or about the size of the Arecibo telescope. Other triple asteroids exist in the asteroid belt (between Mars and Jupiter) and beyond, but this is the first near-Earth system where the actual shapes of objects can be clearly seen. The Arecibo telescope is operated for the NSF by Cornell's National Astronomy and Ionosphere Center. This discovery has extremely important implications for ideas about the origins of near-Earth asteroids and the processes responsible for their physical properties, said Nolan. Double, or binary, asteroid systems are known to be fairly common -- about one in six near-Earth asteroids is a binary -- but this is the first near-Earth triple system to be discovered. The object was first discovered visually Sept. 19, 2001, by the Lincoln Near Earth Asteroid Research (LINEAR) project, part of the Massachusetts Institute of Technology's Lincoln Laboratory. The orbits of binary -- and now triple -- asteroid systems unveil the mass and allow astronomers to assess whether they are stable over millennia or have formed very recently. Previous radar investigations of binary near-Earth asteroids have disclosed extraordinary physical and dynamical characteristics. Nolan said this discovery prompts several important questions: Are the objects orbiting in the same plane? How rapidly are the orbits changing with time? Did the moons form when this asteroid formed in the main asteroid belt, or after it arrived in near-Earth space? Because of the small sizes and irregularly shaped components, 2001 SN263 should offer unique insights relative to the much larger triple systems in the main asteroid belt, said Nolan. Examining the orbits of the moons as we continue to observe 2001 SN263 over the next few weeks may allow us to determine the density of the asteroid and type of material from which it is made, he said. We will also be studying its shape, surface features and regolith [blanketing material] properties. Radar observations by the Arecibo Observatory can image a much larger fraction of the population of near-Earth asteroids than spacecraft. For example, Arecibo has discovered more than half of the near-Earth binary asteroid systems discovered since 1999. Continued observations will undoubtedly lead to the discovery of new classes of objects, such as this triple system. While the Arecibo telescope is capable of these investigations, the future of the radar program and the entire telescope are in considerable doubt due to NSF budget cuts. Nolan's collaborators on the project are Ellen S. Howell, Arecibo Observatory/Cornell University; Lance A.M. Benner, Steven J. Ostro and Jon D. Giorgini, Jet Propulsion Laboratory/California Institute of Technology; Michael W. Busch, Caltech; Lynn M. Carter and Ross F. Anderson, Smithsonian Institution; Chris Magri, University of Maine at Farmington; Donald B. Campbell and Jean-Luc Margot, Cornell; Ronald J. Vervack Jr., Johns Hopkins University Applied Physics Laboratory; and Michael K. Shepard, Bloomsburg University. IMAGE CAPTION: [http://www.news.cornell.edu/stories/Feb08/asteroid.png (8KB)] 2001 SN263 has now been revealed as the first near-Earth triple asteroid ever found. (Arecibo Observatory) __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] DoD To Engage Decaying Satellite
Public Affairs U.S. Department of Defense Office of the Assistant Secretary of Defense Washington, D.C. Media contact: +1 (703) 697-5131/697-5132 IMMEDIATE RELEASE: February 14, 2008 No. 0125-08 DoD To Engage Decaying Satellite An uncontrollable U.S. experimental satellite which was launched in December 2006 is expected to reenter Earth's atmosphere between the end of February and early March. Because the satellite was never operational, analysis indicate that approximately 2,500 pounds (1134 kgs) of satellite mass will survive reentry, including 1,000 pounds (453 kgs) of propellant fuel (hydrazine), a hazardous material. Although the chances of an impact in a populated area are small, the potential consequences would be of enough concern to consider mitigating actions. Therefore, the President has decided to take action to mitigate the risk to human lives by engaging the non-functioning satellite. Because our missile defense system is not designed to engage satellites, extraordinary measures have been taken to temporarily modify three sea-based tactical missiles and three ships to carry out the engagement. Based on modeling and analysis, our officials have high confidence that the engagement will be successful. As for when this engagement will occur, we will determine the optimal time, location, and geometry for a successful engagement based on a number of factors. As the satellite's path continues to decay, there will be a window of opportunity between late February and early March to conduct this engagement. The decision to engage the satellite has to be made before a precise prediction of impact location is available. Contact with hydrazine is hazardous. Direct contact with skin or eyes, ingestion or inhalations from hydrazine released from the tank upon impact could result in immediate danger. If this operation is successful, the hydrazine will then no longer pose a risk to humans. The U.S. government has been and continues to track and monitor this satellite. Various government agencies are planning for the reentry of the satellite. In the event the engagement is not successful, all appropriate elements of the U.S. Government are working together to explore options to mitigate the danger to humans and to ensure that all parties are properly prepared to respond. In the unlikely event satellite pieces land in a populated area, people are strongly advised to avoid the impact area until trained hazardous materials (HAZMAT) teams are able to properly dispose of any remaining hydrazine. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] International Meteor Conference 2008
http://www.imo.net/imc2008/ International Meteor Conference 2008 Sachticka, Slovakia September 18-21, 2008 The International Meteor Organization (IMO) will hold its next annual International Meteor Conference (IMC) Sachticka from September 18 till 21, 2008. Both amateur and professional astronomers are welcome to join us in this four-day event. The location is about 8 km from the city of Banska¡ Bystrica, and about 200 km from the capital Bratislava. The IMC 2008 is organized by the Maximilian Hell District Observatory and Planetarium and the Ziar nad Hronom Observatory of Banská Bystrica. This page provides information for people interested in the IMC and preparing their travel and stay in Slovakia. __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] High Energy Electron Holes Reveal Unseen Rings (Cassini)
http://www.jpl.nasa.gov/news/features.cfm?feature=1611 High Energy Electron Holes Reveal Unseen Rings Jet Propulsion Laboratory February 19, 2008 Gaps in the soup of high energy particles near the orbits of two of Saturn's tiny moons indicate that Saturn may be surrounded by undiscovered, near-invisible partial rings. A paper in the February issue of the journal Icarus suggests the larger Saturnian moons may not be the only ones contributing material to Saturn's ring system. A team of scientists has detected two peculiar breaks in the near-constant rain of high energy electrons that bombard Cassini when near Saturn. They made the discovery using Cassini's Low Energy Magnetospheric Measurement System, a part of the Magnetospheric Imaging Instrument. The gaping holes fall along the orbits of two newly discovered moons, Methone and Anthe. Methone, discovered by Cassini in 2004, is about 3 kilometers across (2 miles), while Anthe, discovered in Cassini images in 2007, is about 2 kilometers wide (1 mile). Both moons are located between the orbits of Mimas and Enceladus. These observations tell us that even Saturn's smallest moons could be a source of dust in the Saturnian system, said Elias Roussos, the paper's lead author from the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany. If the tiny moons are indeed feeding dust into the rings, Roussos says possible future detection and characterization of these rings by more Cassini sensors could provide information about the surface of the moons Methone and Anthe, which are difficult to observe due to their small size. Moons are known to absorb high energy particles. The fact that particles are missing is sensed by Cassini in the same way there are brief moments without rain falling on the windshield when driving under a bridge. These gaps in the flow of electrons showed that something wide was absorbing the charged particles. However, the gaps Cassini saw at Methone and Anthe are so wide, about 1,000 to 3,000 kilometers (600 to 1,900 miles) across, that they cannot be explained solely by the presence of such tiny moons. Instead, the measurements may indicate that the two moons are losing dust from their surface, building up one or more arcs of material along their orbits. Each ring arc is expected to be a few thousand kilometers wide and to comprise large dust grains or dust clumps. The released material may develop into ring arcs due to the gravitational 'tug of war' between Saturn's larger moons, such as Mimas, added Roussos. A similar process has been found to take place at the arc within Saturn's G-ring. Meteoroid impacts on Methone and Anthe are the most likely cause of the release of this material from their surfaces. The same process is thought to have formed Jupiter's faint rings at the orbits of the moons Amalthea, Thebe, Metis and Adrastea. The same situation might be happening at Saturn. In fact, rings of similar origin have also recently been detected in Cassini images along the orbits of the Saturnian moons Janus, Epimetheus and Pallene. What's odd is that these inferred ring arcs still remain undetected in Cassini images, while the rings at Janus, Epimetheus and Pallene orbits, thought to form under the same process, are visible, said Roussos. This means the dust grains making up these two different classes of rings have different characteristics and sizes. However the reason behind this difference is a mystery. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter was designed, developed and assembled at JPL. Media Relations Contact: Carolina Martinez 818-354-9382 __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Cassini Finds Mingling Moons May Share a Dark Past
http://www.jpl.nasa.gov/news/news.cfm?release=2008-028 Cassini Finds Mingling Moons May Share a Dark Past Jet Propulsion Laboratory February 19, 2008 Despite the incredible diversity of Saturn's icy moons, theirs is a story of great interaction. Some of them are pock-marked, some seemingly dirty, others pristine, one spongy, one two-faced, some still spewing with activity and some seeming to be captured from the far reaches of the solar system. Yet many of them have a common thread -- black stuff coating their surfaces. We are beginning to unravel the mysteries of these different and strange moons, said Rosaly Lopes, Cassini scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. She coordinated a special section of 14 papers about Saturn's icy moons that appears in the February issue of the journal Icarus. Taken together, the papers bring an idea that Cassini scientist Bonnie Buratti calls the ecology of the Saturn system to the forefront. Ecology is about your entire environment - not just one body, but how they all interact, said Buratti. The Saturn system is really interesting, and if you look at the surfaces of the moons, they seem to be altered in ways that aren't intrinsic to them. There seems to be some transport in this system. Though the details of that transport are not yet clear, mounting evidence suggests that some mechanism has spread the mysterious dark material found on several of the moons from one to another; the material may even have a common cometary origin. Along those lines, several of the new papers focus on similarities between the dark material found on different moons - on Hyperion and Iapetus, for example, or between Phoebe and Iapetus. Roger Clark of the U.S. Geological Survey in Denver goes further, saying, We see the same spectral signature on all the moons that have coatings of dark material. Clark is lead author of one of the new papers, which focuses on Saturn's moon Dione. His team found the dark material there to be extremely fine-grained, making up only a very thin layer on the moon's trailing side. Its distribution and composition, as measured by the Cassini visual and infrared mapping spectrometer, indicate that the dark material is not native to Dione. And scientists see many of the same signatures there that appear on the moons Phoebe, Iapetus, Hyperion and Epimetheus, and also in Saturn's F-ring. As for where this material comes from and what the dark material is, Clark said, It's a mystery, which makes it intriguing. We're still trying to find the exact match. The visual and infrared spectrometer detected unique absorption bands in the dark material within the Saturn system, which scientists have not seen anywhere else in the solar system. The data keep getting better and better, he said. We're ruling things out and figuring out pieces. So far, the team has identified bound water and, possibly, ammonia in the dark material. Ongoing geologic activity is another component of Saturn's ecology as some of the moons continue to feed the planet's rings, which in turn affect many of the moons. Clark's team reports tentative evidence to support the hypothesis presented earlier this year that Dione is still geologically active. In one series of observations, the infrared spectrometer detected a cloud of methane and water ice encircling Dione in its orbit within the outer portions of Saturn's E-ring. Of course the big story is the icy plumes spewing from the warm, south polar region of Enceladus. These plumes are believed to be feeding the E-ring. A paper led by Frank Postberg of the Max Planck Institute for Nuclear Physics in Heidelberg, Germany, says there are traces of organic compounds or silicate materials within the water ice-dominated E-ring, close to Enceladus. This implies that the moon's rocky core and liquid water are dynamically interacting. The finding could bolster a theory that Dennis Matson and Julie Castillo of JPL put forth this year, which said that a warm, organic brew might lie just below Enceladus' surface. Cassini's next close study of an icy moon is the highly-anticipated flyby of Enceladus scheduled for March 12. During that flyby, Cassini will pass by the active moon at a distance of only 50 kilometers (30 miles) at its point of closest approach, and at a distance of around 200 kilometers (120 miles) when it passes through the plumes. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter was designed, developed and assembled at JPL. Media contact: Carolina Martinez 818-354-9382 Jet Propulsion Laboratory, Pasadena, Calif. [EMAIL PROTECTED] 2008-028 __
