This detail of a Dawn FC (framing camera) image shows an ejecta blanket mantling (eg. covering) the surface and obscuring older caters. The bright crater rim, which can be seen in the middle right edge of this image, is one of a group of craters which are the source of this ejecta blanket. Ejecta blankets are identified as generally smooth areas that consist of debris ejected as craters are formed by impacts. Towards the left side of this image the ejecta blanket begins to die out and older craters, which are not as obscured by the ejecta blanket, become visible. Ejecta blankets can be rather challenging to detect in lower resolution images, so this higher resolution image, as well as those currently being obtained from Dawn’s High Altitude Mapping Orbit (HAMO), will be very helpful in recognizing ejecta blankets. The cluster of small craters, in roughly the center of the image, is due to secondary impacts which are formed by large blocks ejected during the main ejecta forming impact.
NASA’s Dawn spacecraft obtained this image with its framing camera on September 20th 2011. This image was taken through the camera’s clear filter. The distance to the surface of Vesta is 670km and the image resolution is about 63 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://dawn.jpl.nasa.gov.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA