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A Farewell Glance At Endurance As Opportunity Heads
Pasadena (JPL) Dec 13, 2004 Scientists have identified a water-signature mineral called goethite in bedrock that the NASA's Mars rover Spirit examined in the "Columbia Hills," one of the mission's surest indicators yet for a wet history on Spirit's side of Mars. "Goethite, like the jarosite that Opportunity found on the other side of Mars, is strong evidence for water activity," said Dr. Goestar Klingelhoefer of the University of Mainz, Germany, lead scientist for the iron-mineral analyzer on each rover, the Moessbauer spectrometer. Goethite forms only in the presence of water, whether in liquid, ice or gaseous form. Hematite, a mineral that had previously been identified in Columbia Hills bedrock, usually, but not always, forms in the presence of water. The rovers' main purpose is to look for geological evidence of whether their landing regions were ever wet and possibly hospitable to life. The successful results so far - with extended missions still underway - advance a NASA goal of continuing Mars exploration by robots and, eventually, by humans, said Doug McCuistion, Mars Exploration Program Director at NASA Headquarters. Klingelhoefer presented the new results from a rock in the "West Spur" of Mars' "Husband Hill" at a meeting of the American Geophysical Union in San Francisco this week. Spirit has now driven past the West Spur to ascend Husband Hill itself. One remaining question is whether water was only underground or ever pooled above the surface, as it did at Opportunity's site. "As we climb Husband Hill and characterize the rock record, we'll be looking for additional evidence that the materials were modified by ground water and searching for textural, mineralogical and chemical evidence that the rocks were formed in or modified by surface water," said Dr. Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the rover instruments. The amount of worrisome friction in Spirit's right front wheel has been decreasing. Meanwhile, rover wranglers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., continue to minimize use of that wheel by often letting it drag while the other five wheels drive.
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