Terra Tyrrhena/Millochau Crater

This image is located in a region called Terra Tyrrhena within the southern highlands of Mars. The entire image is within the floor of a large crater called Millouchau, which is named after the French astronomer Gaston Millouchau who observed Mars in the late 1800's and early 1900's. This region of mars is known for its heavily cratered and generally eroded and dissected landscape. In this image, there is an erosional feature near the middle of the image with a number of valleys and mesas. There are also a large number of degraded craters with subdued or nonexistent rims. It is not clear how these features formed. One possibility is water, which is an excellent erosional agent. There are few other signs in this image, however, of the presence of surface water in the Martian past. Today, small mega-ripples (a dune form) can be found in the valleys.