13 January 2004
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows troughs eroded into the south polar residual cap. The residual cap is made largely of frozen carbon dioxide, which freezes on Mars at a temperature around 148 Kelvin (about -125°C, -193°F). When this picture was acquired in early summer during October 2003, the temperature at the surface probably was very close to 148 Kelvin (brrrr!). Sunlight illuminates this image from the upper left; it is located near 86.9°S, 15.7°W. The 200 meter scale bar is approximately 656 feet across.