MGS MOC Release No. MOC2-528, 29 October 2003

Fog is a common occurrence in some areas of the retreating south polar seasonal frost cap. Fogs are commonly banked-up against steep slopes or found inside defrosting craters. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image captured mid-afternoon fog banked against the layered walls of Chasma Australe, a trough in the south polar region of Mars. The frost-covered layers of Chasma Australe can be seen on the right side of this image, the billowy fog is to the left. Sunlight illuminates this scene from the upper left. The fog, probably composed of water ice crystals, casts shadows on the chasm wall. This picture is located near 83.5°S, 257.9°W, and covers an area 3 km (1.9 mi) wide.