schwit1 quotes a report from Popular Mechanics: A single underground deposit of ice on Mars contains about as much water as there is in Michigan's Lake Superior, according to new research from NASA. The deposit rests in the mid-northern latitudes of the Red Planet, specifically in the Utopia Planitia region. Discovered by the Shallow Subsurface Radar (SHARD) instrument on the Mars Reconnaissance Orbiter (MRO), the deposit is "more extensive in area than the state of New Mexico," according to a NASA press release. It ranges in thickness from about 260 feet to about 560 feet, and has a composition that's 50 to 85 percent water ice, with what appears to be dust or larger rocky particles mixed in as well. None of the ice is exposed to the surface. At various points the dirt covering it is in between 3 and 33 feet thick.