When I was a kid (mumble mumble) years ago, asteroids were just points of light in even the biggest telescopes. That was true even just a few years ago, but in recent times we've seen quite a few close up thanks to the space program. Vesta is the second largest asteroid, orbiting the Sun in the main belt between Mars and Jupiter. And despite its size (roughly 500 km or 300 miles across), until a few months ago we really didn't know much about it.
But then in July 2011, the spacecraft Dawn arrived. Orbiting the rock, it's been snapping away, revolutionizing our understanding of asteroids. Vesta's landscape is diverse, with craters
, cliffs, mountains, and long, linear grooves (although, interestingly, no hints of vulcanism, when some were expected). Its south pole is an enormous impact basin; something huge
hit Vesta hard
a long time ago. Ejected material from that impact scattered across the solar system, and some of it has hit Earth as meteorites. We've found some of these, and through chemical analysis shown they are from Vesta
, which is truly amazing when you think about it. It took a lot of effort to get a spacecraft to the asteroid, and all that time we had pieces of it here already!