Ares Vallis in Perspective

Ares Vallis in Perspective, a photo by Lunar and Planetary Institute on Flickr.

Via Flickr:
Newly released images taken by ESAʼs Mars Express show an unusual accumulation of young craters in the large outflow channel called Ares Vallis. Older craters have been reduced to ghostly outlines by the scouring effects of ancient water.

Few large craters survive in Ares Vallis; most have been eroded away by flood waters in Marsʼ distant past, probably over 3.8 billion years ago. This crater sits close to Oraibi crater.

There are numerous small craters in the image, appearing both in clusters and in aligned groups. An abundance of such craters can result when an asteroid or other projectile breaks up into many pieces in the atmosphere before crashing to the ground.

Clusters of craters may also be created when a large impact ejects rock fragments with such force that they travel from a few kilometres to hundreds of kilometres before returning to the surface, creating new impacts called secondary craters. The clusters of craters in this image are relatively young on the geological timescale because erosion would have erased them if they had occurred a long time ago.

The image was acquired by Mars Express at about 16°N/327°E during orbit 9393 on 11 May 2011. The images have a ground resolution of 15 m per pixel.