Carbon-Dioxide Snowfall on Mars

Observations by NASA's Mars Reconnaissance Orbiter have detected carbon-dioxide snow clouds on Mars and evidence of carbon-dioxide snow falling to the surface.
Deposits of small particles of carbon-dioxide

ice are formed by snowfall from carbon-dioxide clouds. This map shows the distribution of small-grain carbon-dioxide ice deposits formed by snowfall over the south polar cap of Mars. It is based on infrared measurements by the Mars Climate Sounder instrument on the Mars Reconnaissance Orbiter.