Shape and Gravity of Vesta
This set of images from NASA's Dawn mission shows topography of the giant asteroid Vesta and a map of Vesta's gravity variations.
The top image uses stereo image data from Dawn's framing camera, showing heights relative to a model of Vesta that is an ellipsoid that fits the body's average shape. The terrain varies from 14 miles (22 kilometers) below the average surface (shown in blue) to 12 miles (19 kilometers) above the average surface (shown in red). The map shows Vesta has a complex topography with large basins, uplands, troughs, fractures and grooves.
The bottom image uses data from Dawn's gravity experiment to show gravitational pull in milligal units. Red shows the strongest gravitational pull in this scheme, and dark blue shows the weakest. The gravity data is also mapped onto an ellipsoid model of Vesta.
The topography model is derived from framing camera images from Dawn's survey orbit (on average 1,700 miles or 2,700 kilometers above the surface) and the gravity data come from the low-altitude mapping orbit (130 miles or 210 kilometers above the surface).
Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.