The Messenger space probe sent back this image of the inner planet yesterday, as it flew a few hundred miles above the surface. (This image is from a few thousand miles out, after the flyby.) Most of the planet we see on the right has never before been imaged by spacecraft. That includes the ray system running from that northern crater. Impact ejecta spread across half the surface of Mercury–a few thousand miles.
Messenger continues to tweak its orbit for a future flyby and eventual 2011 insertion into orbit.