Frosted Chasma Boreale Dunes
Jet Propulsion Laboratory https://www.jpl.nasa.gov/ June 16, 2003
MGS MOC Release No. MOC2-390, 13 June 2003
This is a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) view of frost-covered sand dunes in Chasma Boreale in the early northern spring season. Dark spots, some of them with bright halos of re-precipitated frost, have formed as the dunes begin to defrost. Most of the frost is carbon dioxide which freezes out of the atmosphere during the cold martian polar winters. This picture is located near 84.7°N, 358.8°W, and is illuminated from the lower left.