Vesta is almost large enough to fall into what’s called “a relaxed state”; the term for a body with enough mass to pull itself into a sphere, like Earth.
From the NASA Jet Propulsion Laboratory: The View From Vesta
Video Advisory: 2011-293
Sept. 16, 2011
NASA’s Dawn Collects a Bounty of Beauty from Vesta
(The full version of this story with accompanying images is at: http://www.jpl.nasa.gov/news/news.cfm?release=2011-293&cid=release_2011-293)
PASADENA, Calif. – A new video from NASA’s Dawn spacecraft takes us on a flyover journey above the surface of the giant asteroid Vesta.
The data obtained by Dawn’s framing camera, used to produce the visualizations, will help scientists determine the processes that formed Vesta’s striking features. It will also help Dawn mission fans all over the world visualize this mysterious world, which is the second most massive object in the main asteroid belt.
The video, which shows Vesta as seen from Dawn’s perspective, can be viewed at: http://www.jpl.nasa.gov/video/index.cfm?id=1020.
You’ll notice in the video that Vesta is not entirely lit up. There is no light in the high northern latitudes because, like Earth, Vesta has seasons.
Currently it is northern winter on Vesta, and the northern polar region is in perpetual darkness. When we view Vesta’s rotation from above the south pole, half is in darkness simply because half of Vesta is in daylight and half is in the darkness of night .
Another distinct feature seen in the video is a massive circular structure in the south pole region. Scientists were particularly eager to see this area close-up, since NASA’s Hubble Space Telescope first detected it years ago. The circular structure, or depression, is several hundreds of miles, or kilometers, wide, with cliffs that are also several miles high. One impressive mountain in the center of the depression rises approximately 9 miles (15 kilometers) above the base of this depression, making it one of the highest elevations on all known bodies with solid surfaces in the solar system.
The collection of images, obtained when Dawn was about 1,700 miles (2,700 kilometers) above Vesta’s surface, was used to determine its rotational axis and a system of latitude and longitude coordinates. One of the first tasks tackled by the Dawn science team was to determine the precise orientation of Vesta’s rotation axis relative to the celestial sphere.
The zero-longitude, or prime meridian, of Vesta was defined by the science team using a tiny crater about 1,640 feet (500 meters) in diameter, which they named “Claudia,” after a Roman woman during the second century B.C. Dawn’s craters will be named after the vestal virgins-the priestesses of the goddess Vesta, and famous Roman women, while other features will be named for festivals and towns of that era.
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. 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. Other scientific partners include Planetary Science Institute, Tucson, Ariz.; Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany; DLR Institute for Planetary Research, Berlin, Germany; Italian National Institute for Astrophysics, Rome; and the Italian Space Agency, Rome. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft.
You can also follow the mission on Twitter at: http://www.twitter.com/NASA_Dawn .
Priscilla Vega 818-354-1357
Jet Propulsion Laboratory, Pasadena, Calif.