Planetary Pretender: Asteroid Vesta Has Planet-Like Features
NANTES, France--Asteroids are often considered debris, the scraps and odd lumps that went unused in the forming of the planets. But when it comes to Vesta, one of the largest asteroids in our solar system, Chris Russell hardly considers the rock a mere castoff. "I've started calling it the smallest terrestrial planet," said Russell, the principal investigator for NASA's Dawn mission, which sent a spacecraft into orbit at Vesta in July.Russell and his colleagues gave a sense Monday of why they hold Vesta in such high regard. In a press conference here at a joint meeting of the American Astronomical Society Division for Planetary Sciences and the European Planetary Science Congress, researchers working on the Dawn mission announced some of the findings that the spacecraft has collected since entering orbit--findings that make Vesta look considerably more like a world unto itself than a mere leftover. "We found that Vesta is...