NASA's Dawn spacecraft began orbiting Vesta, one of the largest asteroids in the asteroid belt, which lies between Mars and Jupiter. In the above image, a large cliff on Vesta's surface can be seen. Scientists say that the topography surrounding the cliff indicates that huge landslides may have occurred on the slope, but at least parts of the cliff's surface are thought to be quite old, since they display pock marks from small collisions that occur over time. Next summer, Dawn will leave Vesta and head to Ceres, the largest object in the asteroid belt.
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