Autumn in Hellas Basin (edm n. 1 - MULTISPECTRUM-2; credits: Lunexit)

Frost is condensing, and shows up as silver/gray patches in this MULTISPECTRUM image: this is seasonal CO2 frost.

Closer to the Pole, CO2 condenses from the atmosphere and forms a Seasonal Polar Cap. At this latitude we do not expect a thick layer to form but rather the frost collects in cold protected areas on poleward-facing slopes.