CRISM: Ice on rim of crater on Alba Mons

Alba Mons is the largest volcano, by area, on Mars. A low-lying volcano in the northern Tharsis region, Alba Mons has an elevation of 6.8 km, and volcanic flow fields that extend at least 1,350 km from the summit. Alba Mons is one of several areas on Mars that may contain thick deposits of near-surface ice preserved from when the planet’s climate could have allowed mountain glaciers to exist at the mid-latitudes (1 to 10 million years ago). Data collected by the Neutron Spectrometer on Mars Odyssey indicates that the northern flank of Alba Mons might contain up to 7.6% of water-equivalent hydrogen, suggesting the possible presence of water ice today. Since water is not stable on the surface, however, the water would need to be frozen and blanketed by at least 1 m of dust or… [More at link]