New observations from a NASA spacecraft show that the huge asteroid Vesta is a battered protoplanet leftover from the solar system’s early days, with a unique mix ofcharacteristics unknown from any other space rock. Scientists had thought that Vesta, the second-largest body in themain asteroid belt between Mars and Jupiter, probably started down a planet-forming path shortlyafter the solar system’s birth. Data gathered by NASA’s Dawn probe have now confirmed that suspicion, researchers announced in a raftof studies that came out today (May 10) in the journal Science. “We now know that Vesta is the only intact, layered planetary building block survivingfrom the very earliest days of the solar system,” Dawn deputyprincipal investigator Carol Raymond, of NASA’s Jet PropulsionLaboratory in Pasadena, Calif., told reporters today. The other objects like Vesta, researchers added, were probablyincorporated into full-fledged planets or destroyed by collisionslong ago. Satin Drawstring Pouch
[ Photos: Asteroid Vesta by Dawn Probe ] Some surprises “Those studying meteorites that have fallen to Earth, manyfrom Vesta, had produced a theory on the evolution of the solarsystem and what Vesta should be made of,” said Dawn principalinvestigator Chris Russell of UCLA, lead author of one of the sixnew Science papers. “They were very, very right,” Russell told SPACE.com viaemail. “This is good, because we can now use that model tounderstand more about the solar system.” But Dawn has also delivered some surprising new results. Thegigantic Rheasilvia basin at Vesta’s south pole, for example,apparently was created by a massive impact just 1 billion years agoor so — long after the solar system’s collision-filled”shooting gallery” stage is thought to have ended. Mesh Gift Bags Manufacturer
“An age of about 1 billion years for Rheasilvia isunexpectedly young,” Simone Marchi of the Southwest ResearchInstitute in Boulder, Colo., lead author of another of the newpapers, said in a statement. “This result has importantimplications for our understanding of the evolution of Vesta, its asteroid family and the inner main asteroid belt in general.” “We have just started exploring Vesta”s secrets , and I”m sure other intriguing results will come alongshortly,” Marchi added. The protoplanet Vesta With a diameter of about 330 miles (530 kilometers), Vesta isroughly as wide as the U.S. state of Arizona. In the main asteroidbelt, only the dwarf planet Ceres is bigger. Leather Drawstring Pouch Manufacturer
The $466 million Dawn spacecraft arrived at the huge asteroid inJuly 2011 to help unlock its many secrets. One of the probe’s mainmissions, researchers said, is to determine if Vesta is indeed along-surviving protoplanet — a body left over from the solarsystem’s first few million years, many of which later coalesced toform rocky planets such as Earth and Mars . Scientists got this idea mainly by examining fallenhowardite-eucrite-diogenite (or HED) meteorites, which are thoughtto come from Vesta. The new Dawn results strongly support theprotoplanet notion — by confirming that Vesta is indeed theHED meteorites’ parent body, for starters.