The layers exposed in the south polar residual cap, provide a vivid detail of the climate history of Mars over the last 100 million years or so. The materials that comprise the south polar layers may include frozen carbon dioxide, water ice, and fine dust. In the lower left of the image a complex erosional pattern has developed on the south polar cap, perhaps by a combination of sublimation, wind erosion, and ground-collapse. These images were acquired by the Mars Orbiter Camera aboard the Mars Global Surveyor spacecraft during the southern spring season in October 1999. They show features at the scale of a small house.
Sunlight illuminates each scene from the left.
After a quick fly through of the rest of Sol, the 31st Annual Lunar and Planetary Science Conference came back to the subject of Mars dedicating two days to a thorough debate over whether Mars Meteorite ALH84001 contains evidence of ancient Martian microbes.