The Lunar Reconnaissance Orbiter has been circling the Moon since 2009, taking thousands of images in amazing resolution unseen since Apollo. Many of these pictures have been simply astonishing, including the one above taken in March 2011: an unnamed crater a few kilometers across (the image is 2.2 km or about 1.4 miles wide). Whatever smacked into the Moon all those eons ago blew out a lot of dust and other material that fell back to the surface, spreading out like the broad petals of a flower. In the crater floor you can barely see some boulders and other debris that must have gone straight up and back down after the impact. The Moon has no air, but formations like this erode after time anyway: countless meteorite impacts, the solar wind, and even thermal flexing during the Moon's day/night cycle take their toll. So we know that such craters must be young, but that's a relative term: this impact may have occurred when dinosaurs still walked the Earth.
Image credit: NASA/GSFC/Arizona State UniversityOriignal imageOriginal blog post