2016-11-25. An Ice Sheet the Size of New Mexico Hidden in Martian Crater.

posted Nov 30, 2016, 1:31 PM by Alan Gould

By Kenneth Chang, The New York Times. For GSS A Changing Cosmos chapter 7. Excerpt: An ice sheet with more water than Lake Superior may slake the thirst of future astronauts living on Mars. Using radar soundings from NASA’s Mars Reconnaissance Orbiter spacecraft, scientists probed what lies in Utopia Planitia, a 2,000-mile-wide basin within an ancient impact crater. For decades, the region looked intriguing because of polygonal cracking and scalloped depressions in the landscape. In places on Earth like the Canadian Arctic, patterns like these arise from ice beneath the surface. The ground cracks as ice underneath expands and contracts with the changing temperatures; the scallops, as if carved by an ice cream scoop, are places where the surface sinks as the ice melts. “We’d say, ‘It looks like there’s ground ice there,’” Cassie Stuurman, a graduate student at the University of Texas at Austin, said about Utopia Planitia. “What we haven’t known is how much is there.”n ...Ms. Stuurman, the lead author of an article in the journal Geophysical Research Letters that described the findings, said the radar reflections revealed that the ice sheet, ranging in thickness from 260 to 560 feet, covered an area larger than New Mexico.  ...Water ice is plentiful at the Martian poles, but Utopia Planitia might be a more attractive landing site for future astronauts, because it is in the more temperate mid-northern latitudes....  http://www.nytimes.com/2016/11/25/science/mars-ice-sheet.html