Spacecraft 'peels back' asteroid's surface

The Dawn spacecraft revealed details about the asteroid Vesta, including surface composition and clues to its internal structure, scientists said in Austria. An analysis of the Dawn data was presented Tuesday at the European Geosciences Union meeting in Vienna, NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported. Visual and infrared imaging of Vesta show a variety of surface mineral and rock patterns, researchers said, providing insights into the giant asteroid's composition and allowing them to identify material that was once molten below the asteroid's surface. Researchers said the images show breccias -- rocks fused during impacts from space debris. "Dawn now enables us to study the variety of rock mixtures making up Vesta's surface in great detail," Harald Hiesinger, a Dawn participating scientist at Munster University in Germany, said. "The images suggest an amazing variety of processes that paint Vesta's surface." The findings suggest the surface of Vesta is anything but static, researchers said. "These results from Dawn suggest Vesta's 'skin' is constantly renewing," Maria Cristina De Sanctis of Italy's National Institute for Astrophysics in Rome said.