The is the Dawn spacecraft's view of the asteroid Vesta. Dawn is the NASA mission that will visit two asteroids, beginning with Vesta in a few weeks, and then Ceres in 2015. Dawn will go into orbit about Vesta on July 16 to study that asteroid's surface for about a year. Vesta is about 300 miles across and is the fourth largest asteroid. Vesta's surface is composed of basaltic rock, or lava, which makes this asteroid quite unique and very interesting. Evidently Vesta was volcanically active in the past, likely when it first formed 4.5 billion years ago.
In July 2012, Dawn will then fire up its ion engine and depart Vesta for its 3 year trip to asteroid Ceres, which is the largest asteroid, one that appears to be quite rich in water. Meanwhile, keep an eye on the Dawn mission website for better pictures of Vesta that will soon get much more interesting when the spacecraft goes into orbit.