Man, Vesta is weird. It's a 500 km (300 mile) wide asteroid, the second biggest, so its gravity should be strong enough to crush it into a sphere. But it's not a ball; it's lumpy and stretched out and, weirdest of all, has an enormous circular depression at its south pole which flattens that entire hemisphere of the little world. Here's a recent image taken by the Dawn spacecraft, looking down on Vesta's strange southern region:
[Click to envestanate.] You can tell it's not round! It's like looking up at a pancake held over your head. The Sun angle is such that the left hand side of the rock is in darkness, which actually helps with giving the image some relief and perspective. My first assumption is that something really big hit Vesta a long time ago, carving out that basin. Central peaks are common in events like that, smack ...
