For decades, planetary geologists have speculated that glaciers might once have crept through Valles Marineris, the 2000-mile-long chasm that constitutes the Grand Canyon of Mars. Using satellite images, researchers have identified features that might have been carved by past glaciers as they flowed through the canyons; however, these observations have remained highly controversial and contested.
Fuente : http://www.alphagalileo.org/ViewItem.aspx?ItemId=1...
Fuente : http://www.alphagalileo.org/ViewItem.aspx?ItemId=1...