spacetoday.net: Buried glaciers found on Mars

Posted: Fri, Nov 21, 2008, 8:09 AM ET (1309 GMT)
Mars glacier illustration (NASA/JPL)

Scientists using a radar instrument on a NASA orbiter have detected giant glaciers of water ice buried beneath the surface of Mars. In a paper published in Friday's issue of the journal Science, a team of scientists reported on the discovery of the glaciers, made using the radar on the Mars Reconnaissance Orbiter spacecraft. Radar waves are able to penetrate the upper layers of the Martian surface; observations in several areas showed that, in several areas, the signals reflected off a deeper layer without a significant loss in strength, consistent with the waves passing through a region of primarily water ice. Those regions are known as aprons, gently sloping regions whose nature had puzzled geologists since they were first spotted in Viking images in the 1970s. Scientists now believe that the aprons contain glaciers covered with a thin layer of rock. In one case the subterranean glacier is three times the size of Los Angeles and nearly a kilometer thick. These glaciers are thought to be the largest deposits of water ice on Mars outside the polar regions.