[meteorite-list] Mars Odyssey THEMIS Images: May 23-27, 2016
MARS ODYSSEY THEMIS IMAGES May 23-27, 2016 o Olympia Undae (23 May 2016) http://themis.asu.edu/zoom-20160523a o Steinheim Crater (24 May 2016) http://themis.asu.edu/zoom-20160524a o Olympica Fossae (25 May 2016) http://themis.asu.edu/zoom-20160525a o Boreum Cavus (26 May 2016) http://themis.asu.edu/zoom-20160526a o Nilokeras Fossa (27 May 2016) http://themis.asu.edu/zoom-20160527a All of the THEMIS images are archive 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. __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] NASA Radar Finds Ice Age Record in Mars' Polar Cap
http://www.jpl.nasa.gov/news/news.php?feature=6519 NASA Radar Finds Ice Age Record in Mars' Polar Cap Jet Propulsion Laboratory May 26, 2016 Scientists using radar data from NASA's Mars Reconnaissance Orbiter (MRO) have found a record of the most recent Martian ice age recorded in the planet's north polar ice cap. The new results agree with previous models that indicate a glacial period ended about 400,000 years ago, as well as predictions about how much ice would have been accumulated at the poles since then. The results, published in the May 27 issue of the journal Science, help refine models of the Red Planet's past and future climate by allowing scientists to determine how ice moves between the poles and mid-latitudes, and in what volumes. Mars has bright polar caps of ice that are easily visible from telescopes on Earth. A seasonal cover of carbon-dioxide ice and snow is observed to advance and retreat over the poles during the Martian year. During summertime in the planet's north, the remaining northern polar cap is all water ice; the southern cap is water ice as well, but remains covered by a relatively thin layer of carbon dioxide ice even in southern summertime. But Mars also undergoes variations in its tilt and the shape of its orbit over hundreds of thousands of years. These changes cause substantial shifts in the planet's climate, including ice ages. Earth has similar, but less variable, phases called Milankovitch cycles. Scientists use data from MRO's Shallow Subsurface Radar (SHARAD) to produce images called radargrams that are like vertical slices though the layers of ice and dust that comprise the Martian polar ice deposits. For the new study, researchers analyzed hundreds of such images to look for variations in the layer properties. The researchers identified a boundary in the ice that extends across the entire north polar cap. Above the boundary, the layers accumulated very quickly and uniformly, compared with the layers below them. "The layers in the upper few hundred meters display features that indicate a period of erosion, followed by a period of rapid accumulation that is still occurring today," said planetary scientist Isaac Smith, the study's lead author. Smith led the work while at Southwest Research Institute in Boulder, Colorado, but is now at the Planetary Science Institute in Tucson, Arizona. On Earth, ice ages take hold when the polar regions and high latitudes become cooler than average for thousands of years, causing glaciers to grow toward the mid-latitudes. In contrast, the Martian variety occurs when -- as a result of the planet's increased tilt -- its poles become warmer than lower latitudes. During these periods, the polar caps retreat and water vapor migrates toward the equator, forming ground ice and glaciers at mid-latitudes. As the warm polar period ends, polar ice begins accumulating again, while ice is lost from mid-latitudes. This retreat and regrowth of polar ice is exactly what Smith and colleagues see in the record revealed by the SHARAD radar images. An increase in polar ice following a mid-latitude ice age is also expected from climate models that show how ice moves around based on Mars' orbital properties, especially its tilt. These models predict the last Martian ice age ended about 400,000 years ago, as the poles began to cool relative to the equator. Models suggest that since then, the polar deposits would have thickened by about 980 feet (300 meters). The upper unit identified by Smith and colleagues reaches a maximum thickness of 1,050 feet (320 meters) across the polar cap, which is equivalent to a 2-foot-thick (60-centimeter-thick) global layer of ice. That is essentially the same as model predictions made by other researchers in 2003 and 2007. "This suggests that we have indeed identified the record of the most recent Martian glacial period and the regrowth of the polar ice since then. Using these measurements, we can improve our understanding of how much water is moving between the poles and other latitudes, helping to improve our understanding of the Martian climate," Smith said. After 10 years in orbit, Mars Reconnaissance and its six science instruments are still in excellent shape. "The longevity of the mission has enabled more thorough and improved radar coverage of the Martian poles," said Richard Zurek, the mission's project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. "Our long life in orbit and powerful 3-D analysis tools are allowing scientists to unravel Mars' past climate history." The Italian Space Agency provided the SHARAD instrument on Mars Reconnaissance Orbiter and Sapienza University of Rome leads its operations. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver built the orbiter and supports its op
[meteorite-list] NASA Response to Recent Paper on NEOWISE Asteroid Size Results
http://www.jpl.nasa.gov/news/news.php?feature=6518 NASA Response to Recent Paper on NEOWISE Asteroid Size Results Jet Propulsion Laboratory May 25, 2016 A paper posted Sunday by Nathan Myhrvold to ArXiv.org and described in an article by reporter Ken Chang in the May 23 New York Times discusses interpretations of data on asteroids from NASA's NEOWISE mission. The paper was posted before undergoing the essential scientific peer-review process to catch and remove significant errors. Examination of the paper by members of the science community studying near-Earth objects has found several fundamental errors in Myhrvold's approach and analysis-mistakes that an independent peer review process is designed to catch. The errors in the paper lead to results that are easily refuted, such as sizes for well-known asteroids that are significantly larger or smaller than their already-verified sizes. While critique and re-examination of published results are essential to the scientific process, it is important that any paper undergo peer review by an independent journal before it can be seriously considered. This completes a necessary step to ensure science results are independently validated, reproducible, and of value to the science community. All of the published NEOWISE team papers providing their results have endured the peer-review process. NASA is confident that the processes and analyses performed by the NEOWISE team are valid and verified and stands by its data and scientific findings. Data from the NEOWISE mission is available on a website for the public and scientific community to use. A guide to the NEOWISE data release, data access instructions and supporting documentation is available at http://wise2.ipac.caltech.edu/docs/release/neowise/. Access to the NEOWISE data products is available via the on-line and API services of the NASA/IPAC Infrared Science Archive. A list of peer-reviewed papers using the NEOWISE data is available at http://neowise.ipac.caltech.edu/publications.html News Media Contact DC Agle / Veronica McGregor 818-393-9011 / 818-354-9452 a...@jpl.nasa.gov veronica.mcgre...@jpl.nasa.gov 2016-134 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Fireball Over Mexico on May 21
http://mexiconewsdaily.com/news/ball-of-fire-explosion-witnessed-in-3-states/ Ball of fire, explosion witnessed in 3 states Mexico Daily News May 21, 2016 There is speculation that a meteorite landed last night in Puebla A brilliant flash of light followed by an explosion early this morning have led observers to conclude that a meteorite has fallen somewhere in the state of Puebla. Photos and videos in which a bright object is seen in the sky began appearing on social media just before 2:00am. Video cameras operated by Webcams de Mexico picked up the object itself from two locations in Mexico City as it entered the Earth's atmosphere. Cameras in Puebla and Tlaxcala showed the intensity of the bright light as the object passed by. One Twitter user reported that 20 seconds after seeing a ball of fire in the sky over Puebla there was a strong explosion. The state's Civil Protection office said this morning it is working with firefighters in several areas of the state to determine whether it was indeed a meteorite that landed. The Puebla Astronomical Society weighed in on Twitter by observing that the loud explosion heard by people in Mexico City, Puebla and Tlaxcala didn't necessarily mean it was a meteorite that had landed on Earth. The society said it was more likely a meteor that exploded in the atmosphere. Puebla Civil Protection director Fernando Estrella ruled out the suggestion that the explosion might have come from the volcano Popocatépetl. __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] Meteorite Picture of the Day
Today's Meteorite Picture of the Day: Chelyabinsk Contributed by: M. Schulman http://www.tucsonmeteorites.com/mpodmain.asp?DD=05/27/2016 __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
