Planum Australe / Planum Boreum

Mars has polar ice caps. They consist of primarily water-ice with a few percent dusts. Frozen carbon dioxide makes up a small permanent portion of the Planum Australe or the South Polar Layered Deposits. In both hemispheres a seasonal carbon dioxide frost deposits in the winter and sublimes during the spring. Planum Australe is the southern polar plain on Mars. Planum Boreum is the northern polar plain on Mars. The polar cap of Mars has been proposed as a landing site for a human Mars expedition.