The giant asteroid Vesta more closely resembles a small planet or Earth's moon than other asteroids, data returned by NASA's Dawn space probe show, dpa reported. Images taken by the Dawn, which has been orbiting Vesta since last year, provide key clues into the early universe when the asteroid formed, and show it began its life as a planetary building block. Results of the report appeared Thursday in the journal Science. The 4.56-billion-year-old asteroid has a rare iron core, and a crust and mantle like a planet, forming in a similar way to the Earth and its moon. It likely once harboured a sub-surface magma ocean, a feature that often leads to the formation of layers that form planets. Vesta is the largest source of meteorites that reach Earth, providing scientists with the first up-close look at the source of such space rocks. The meteorites' composition matches Vesta, which scientists said provides 6 per cent of Earth's meteorites. Scientists got a close look at Vesta's craters, slopes and peaks and were able to date two basins created by large impacts to 1 billion and 2 billion years ago. Dawn, which was launched in 2007 by the US space agency, is to offer insights into the beginning of the universe by examining rocky objects that date to the time when planets were forming in the solar system. After examining Vesta, Dawn will continue on to the dwarf planet Ceres, elsewhere in the asteroid belt.
