Ray craters in Vesta’s south polar region: Nasa Dawn Mission Image of the Day Gallery 8 Oct 2011

This detail of a Dawn FC (framing camera) image shows many fresh craters, several with bright ejecta rays, which were formed by impacts into the floor of Vesta’s south polar basin. The three most distinctive rayed craters are in the top and middle of the image and each has a clear raised crater rim.  Ejecta rays form when material is thrown out of a crater during an impact. These ejecta rays most commonly have a higher albedo (are brighter) than the surrounding surface, as is the case here. Sometimes larger masses of ejecta form small secondary craters near these ejecta rays. Even though this image resolves numerous small craters, only a few hundred meters across, higher resolution imagery is necessary to identify secondary craters in this case. The rayed craters also contain enigmatic low albedo dark material, which is seen across Vesta. The distinctive hummocky (eg. wavy/ undulating) terrane of Vesta’s south polar region is evident throughout this image as well.

NASA’s Dawn spacecraft obtained this image with its framing camera on September 9^th 2011. This image was taken through the camera’s clear filter. The distance to the surface is 1390km and the image resolution is about 130 meters per pixel.

Image Credit: NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA