NASA's biggest achievement was certainly the landing of men on the moon in the 60's and early 70's. While we were putting men onto the moon decades ago, the limited budget of NASA has kept manned missions off the books and most of the exploration has been done by unmanned spacecraft. Over the weekend NASA's unmanned Dawn spacecraft entered orbit around a giant asteroid in our asteroid belt called Vesta.
Dawn is now the first spacecraft to ever orbit an object in the asteroid belt. Vesta is a giant asteroid about as wide as Arizona at 330 miles wide. It’s so large that some astronomers consider the asteroid a proto-planet. Dawn arrived at the asteroid after four-years in route and it will study the asteroid for the next year before blasting off to orbit an even larger asteroid called Ceres.
Ceres is so large is called a dwarf planet at about 590 miles wide. Dawn will orbit Ceres sometime in 2015. Among the things that Dawn hopes to discover about Vesta is what makes the asteroid so bright. The voyage for Dawn so far as been 1.7 million miles.