Dawn

Dawn orbited the protoplanet Vesta and is now in orbit around the dwarf planet Ceres as part of its mission to characterize the conditions and processes that shaped our solar system. Vesta and Ceres are the two most massive bodies in the main asteroid belt between Mars and Jupiter. By studying these two giant remnants from the epoch of planet formation, Dawn will provide scientists with new knowledge of how the solar system formed and evolved.

Thanks to its ion propulsion system, Dawn is the only spacecraft ever to have the capability to orbit two extraterrestrial destinations.

Dawn's science investigations at Vesta result in a number of findings about the protoplanet:

• Vesta is more closely related to the terrestrial planets (including Earth) than to typical asteroids. Like planets, it has a dense core, surrounded by a mantle and a crust.
• Vesta has a crater more than 300 miles in diameter. In the center is a mountain more than twice the height of Mount Everest.
• Vesta has a network of more than 90 chasms -- some with dimensions rivaling those of the Grand Canyon -- that are scars from two giant impacts hundreds of miles away.
• Vesta is the source of more meteorites on Earth than Mars or the moon.