Martian crater with hoarfrost deposits along its southern rim
Martian crater with hoarfrost deposits along its southern rim
During winter in each hemisphere, the seasonal ice caps at the Martian north and south poles extend to approximately 50 degrees latitude. As this happens, carbon dioxide ice crystals precipitate from the cold atmosphere onto the surface. These deposits persist beyond the winter months and remain into the first weeks of spring. In the crater on the left, such a hoarfrost field can be seen along the inner southern rim.