Evidence of ancient lakes, rivers found in clay Martian soil

by William Atkins

Friday, 18 July 2008

Page 1 of 2 ! The NASA Mars Reconnaissance Orbiter (MRO) has provided new data to scientists that show a host of “wet environments” existed billions of years ago on Mars. Scientists describe the amount of ancient Martian water as “pervasive and long-lasting.” According to the NASA news release, “NASA spacecraft shows diverse, wet environment on ancient Mars,” the MRO spacecraft—based on two important studies—has found that Mars “… once hosted vast lakes, flowing rivers, and a variety of other wet environments that had the potential to support life.” The result of one of the two studies was published in the July 17, 2008 issue of the journal Nature. Its title is “Hydrated silicate minerals on Mars observed by the Mars Reconnaissance Orbiter CRISM instrument.” The authors of the article are: John F. Mustard, Bethany L. Ehlmann, S. L. Murchie, S. M. Pelkey, and a host of other scientists. According to data provided by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), the Context Imager (CTX), the High Resolution Imaging Science Experiment (HiRISE) camera, and other instruments onboard the MRO spacecraft, the conclusion of the Nature article states that the ancient highlands of Mars, about half of the planet, are composed of clay minerals. Water was present in these highlands about 4.6 to 3.8 billion years ago. Later, as drier conditions altered the Martian environment, volcanic lava flowed over the clay—burying it underground. However, over the following billions of years, comets, asteroids, and meteors and other bodies impacted the planet. The resulting impact craters once again exposed the clay at thousands of locations on Mars, allowing the MRO instruments to analyze them. CRISM principal investigator Scott Murchie, of the Applied Physics Laboratory at the Johns Hopkins University (Laurel, Maryland), responds to the discovery, “The big surprise from these new results is how pervasive and long-lasting Mars' water was, and how diverse the wet environments were.” In addition, CRISM team member John Mustard, from the Department of Geological Sciences Brown University (Providence, Rhode Island), states, “The minerals present in Mars' ancient crust show a variety of wet environments. In most locations the rocks are lightly altered by liquid water, but in a few locations they have been so altered that a great deal of water must have flushed though the rocks and soil. This is really exciting because we're finding dozens of sites where future missions can land to understand if Mars was ever habitable and if so, to look for signs of past life." In the abstract to their paper, the researchers point out, “These results point to a rich diversity of Noachian environments conducive to habitability.” The second study looks at these clay minerals around the Jezero Crater on Mars. Please read on. << First page <   1 2 Next page > Last page - Post your comment >>

 

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