ESA’s Mars Express continues to provide new views of the martian surface, as in this image of a strikingly elongated crater in the southern hemisphere, south of Huygens crater. (Martian north is to the right in this image.)
The crater is probably the result of the impact of two or more projectiles, landing close together, an idea reinforced by the existence of a second elongated crater, to the northwest of this one, and aligned with it. Principal lines of evidence for a multiple impact are the shape of the ejecta blanket around the crater, and the variable depth of the crater floor. The crater is about 78 km long and from 10 to 25 km across. It is up to 2 km deep, but has three deeper areas suggesting several impacts. The ejecta blanket also shows distinct lobes, which may come from two closely spaced impacts; the impactors may have originally been parts of the same body.
As well as providing a snapshot of the impacts that shaped the surface of the planet, this image also shows processes at work on the martian surface. The debris blanket is cut by several small channels, suggesting that at the time of the impact, the surface was rich in volatiles, perhaps even water, that were melted by the heat of impact and flowed away.
The image was created using a Digital Terrain Model (DTM) obtained from the High Resolution Stereo Camera on Mars Express and is colour coded for elevation: purple indicates the lowest lying regions and grey the highest.