Etched Terrain

This stunning THEMIS visible image was acquired in 'etched terrain' near the south pole of Mars. In several places in this image there are large areas with many dark spots. These spots have been noticed to appear and disappear as the seasons progress on Mars. As the southern hemisphere of Mars gets warmer, carbon dioxide frost present in this terrain sublimates, leaving behind the dark spots. Small dark dunes are visible towards the bottom of the image.