Apparent Brightness and Topography Images of Urbinia and Sossia Craters

The left-hand image is a Dawn FC (framing camera) image, which shows the apparent brightness of Vesta's surface. The right-hand image is based on this apparent brightness image, which has had a color-coded height representation of the topography overlain onto it. The topography is calculated from a set of images that were observed from different viewing directions, which allows stereo reconstruction. The various colors correspond to the height of the area. The white and red areas in the topography image are the highest areas and the blue areas are the lowest areas. Urbinia crater is the large, irregularly shaped crater in the left corner of the image. Sossia is the middle-sized crater, containing dark material, in the center of the bottom right edge of the image. The irregular shape of Urbinia crater is probably due to a number of smaller craters being formed on its rim. Then these smaller craters and the rim of Urbinia merge together, probably due to the mass movement of material towards the center of Urbinia. From the topography image it can be seen that the lowest point in Urbinia (shaded blue) is offset from the center of the crater. This could be due to the fact that Urbinia formed on a slope. This slope is shaded from red to green in the top part of the topography image. The apparent brightness image shows that there is much more distinctive bright and dark material in Sossia crater than in Urbinia crater.

These images are located in Vesta's Urbinia quadrangle, in Vesta's southern hemisphere. NASA's Dawn spacecraft obtained the apparent brightness image with its framing camera on Oct. 13, 2011. This image was taken through the camera's clear filter. The distance to the surface of Vesta is 700 kilometers (435 miles) and the image has a resolution of about 70 meters (230 feet) per pixel. This image was acquired during the HAMO (high-altitude mapping orbit) phase of the mission. These images are lambert-azimuthal map projected.

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.