Radial Channels Carved by Dry Ice

Mars’ carbon dioxide atmosphere partially condenses every winter to form polar caps of dry ice. In the spring, the evaporation of the ice is a dynamic process and carves channels into the ground as it escapes back into the atmosphere.

Often these channels are radial in nature, and are colloquially referred to as “spiders,” although the preferred term for these radially-organized channels is “araneiform” which means spider-like.

In this subimage all the seasonal frost is gone, and we can use stereo images or shadow measurements to measure the depth of the channels carved into the ground, typically 1 - 2 meters deep.

Photo credit: NASA/JPL/University of Arizona

Note: The location of this image is in Planum Australe, three degrees from the Martian South Pole.