Rilles on Vesta's Surface
This Dawn FC (framing camera) image shows small scars (known as rilles) on Vesta's surface, which are mostly concentrated in the right half of the image. They are presumably due to impacts throwing out boulders, which then crash across the surface scouring the rilles as they go. Such boulders are visible as tiny black dots, due to their shadows, in the top right of the image. They are just underneath a bright patch, which is the edge of an impact crater. This impact crater could be where these boulders originated. In the top left of the image short rilles cut across partially infilled impact craters.
NASA's Dawn spacecraft obtained this image with its framing camera on October 3rd 2011. This image was taken through the camera's clear filter. The distance to the surface of Vesta is 670km and the image has a resolution of about 66 meters per pixel.
The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington D.C. UCLA is responsible for overall Dawn mission science. The Dawn framing cameras have been developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, with significant contributions by DLR German Aerospace Center, Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The Framing Camera project is funded by the Max Planck Society, DLR, and NASA/JPL.
More information about Dawn is online at http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov.