Large blocks of rocky material in a young ray crater: Nasa Dawn Mission Image of the Day Gallery 22 Nov 2011

This Dawn FC (framing camera) image shows a young, fresh crater, which is about 7 km in diameter, in the lower right part of the image. This crater has both dark and bright rays fanning out from it. The bright rays extend much farther from the crater than the dark rays, which are located close to the crater rim. Rays around a crater are formed when relatively small sized pieces of material are ejected by the impact that formed the crater. When larger pieces of material are ejected they can form secondary craters. Clusters and chains of sub-kilometer diameter secondary craters occur roughly 15 km to 20 km away from the rim of the 7 km crater. They are called secondary craters because the blocks that formed them were ejected from a crater formed by a primary impact. Sometimes blocks fall back into the initial crater. Many of these blocks can be seen on the floor and walls of the 7 km diameter crater. These blocks are several tens of meters in size.

This image is centered in Vesta’s Tuccia quadrangle and the center latitude and longitude of the image is 22.8°S, 217.3°E. NASA’s Dawn spacecraft obtained this image with its framing camera on November 8, 2011. This image was taken through the camera’s clear filter. The distance to the surface of Vesta is 478 km and the image has a resolution of about 45 meters per pixel. This image was acquired during the transfer to LAMO (Low Altitude Mapping Orbit) phase of the mission.

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