This Southern hemisphere crater has gullies on its North and Northeast walls. Gullies are proposed to be carved by liquid water originating from the subsurface or melting ice/snow on the surface.

Arcuate ridges, wave-shaped high-standing features, are located downslope of the gullies here. This happens frequently on Mars, although it is unknown whether the formation of gullies and arcuate ridges are related to each other.

Dark dunes are visible on the crater floor. Lighter, smaller dunes rim the south side of the crater floor. The entire scene has a pitted texture, suggesting that ground ice was once present in this region. When ground ice sublimates (goes from a solid directly to a gas), it leaves behind empty spaces in the soil that turn into pits as the remaining overlying soil collapses to fill them.

Written by: Kelly Kolb   (25 March 2009)

This is a stereo pair with ESP_012496_1410 .

More info and image formats at http://hirise.lpl.arizona.edu/ESP_011995_1410

Image: NASA/JPL/University of Arizona