South Polar Knob
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a small, relatively light-toned knob of layered material, and the erosional expression of the underlying layers, in the south polar region of Mars. When the image was acquired in April 2005, the surface was still covered with seasonal carbon dioxide frost. Dark spots and streaks mark locations where the frost had begun to change and sublime away.
Location near: 84.2Â°S, 138.3Â°W
Image width: ~3 km (~1.9 mi)
Illumination from: upper left
Season: Southern Spring