(I was going to call this post “Dawn breaks at Vesta” but that might have given the false impression that Dawn literally broke in orbit and isn’t working anymore 😉 )
Dawn successfully entered Vesta orbit in the weekend, and has returned the first pictures from Vesta orbit!
The big lump in the middle of the asteroid is actually the central peak of a massive crater caused by an impact that literally blew away most of the protoplanet’s southern hemisphere! There are all sorts of interesting things to see here – lots of bowl-shaped craters, grooved/scallopped terrain in the big crater floor, and what looks like a huge cliff marking part of the rim of the big crater!
There’s also a very nice image showing another view of Vesta’s ‘south pole crater’, along with other asteroids that we’ve sent spacecraft to shown to the same scale:
Vesta is about 530 km in diameter, so it’s pretty large for an asteroid – it’s the third largest in the asteroid belt – and is far bigger than Lutetia, which was previously the record holder for ‘largest asteroid visited by a spacecraft’. Dawn will move on to visit Ceres next year, which is the largest asteroid in the asteroid belt and (unlike Vesta) is actually spherical too.
We’ll see more of Vesta as Dawn maps it from orbit over the next year – this only the beginning, and I’m very excited to see what else will be revealed! (You can find out more about the Dawn mission at its official website)