Dawn Begins Orbiting Vesta

NASA's Dawn spacecraft began orbiting the asteroid Vesta on Saturday, July 16, 2011, thus becoming the first spacecraft to orbit an object in the asteroid belt, located in between Jupiter and Mars.

Dawn will study Vesta until July 2012, when it will move on to the dwarf planet Ceres, which is also located in the asteroid belt.

NASA launched Dawn in 2007. Once it begins orbiting Ceres, Dawn will have become the first spacecraft to orbit two different Solar System objects outside the Earth.

Vesta and Ceres are the two largest protoplanets in the Solar system.  Protoplanets are objects that began to develop into planets, but never grew to the size of a full planet.

The growth of Ceres and Vesta was halted when Jupiter was formed.

These two protoplanets went on very different evolutionary paths during the first few million years of their existence.   Ceres is a primitive, wet planet; Vesta is drier and more evolved.

Scientists believe that by studying Vesta and Ceres, they will learn more about the creation and evolution of the Solar System.