NASA scientists are having a lot of fun with Messenger, the spacecraft now orbiting Mercury. Not only they are documenting the planet at a resolution of 200m per pixel, but they are spotting all kinds of fun stuff. A few weeks ago it was the Sesame Street's cookie monster. Today it's a smiley crater.
It looks like even the craters on Mercury have heard of Bob Ross! The central peaks of this complex crater have formed in such a way that it resembles a smiling face. This image is oriented so north is toward the bottom.
So far, Messenger has taken 88,746 images "and extensive other data sets". After completing its primary mission — and still working like a champ — the spacecraft is going to capture another 80,000 images. [NASA Goddard]