Global view of Vesta centred on the south-polar depression

Global view of Vesta centred on the south-polar depression
This image shows the south pole of, the third largest object in the asteroid belt. When NASA’s Dawn spacecraft approached asteroid Vesta in mid 2011, the science team was particularly eager to see the first images of its south pole.
Images the Hubble Space Telescope had collected years before with low resolution showed a depression of several hundred kilometres in diameter at the asteroids’ south pole, perhaps the result of a giant impact the asteroid experienced in its early history. The first images from the survey orbit of Dawn have confirmed that the circular depression is real. The images Dawn returned from its July and August survey orbit at 2420 kilometres altitude above the surface, have scientists discussing whether the circular structure dominating this image was caused by a collision with another asteroid, or by internal processes operating early in the asteroid’s history. Images in higher resolution from Dawn’s lower orbits might help answer that question.