Barely 15 years after Comet Shoemaker-Levy slammed into Jupiter, another large object hit Jupiter this month when nobody was looking. This image was taken 4 days after the event and displays an Earth-sized scar in the upper atmosphere of the planet. The object that did the slamming is estimated to have been about the size of several football fields. This should be a fairly rare event, although twice in 15 years is literally a blip on a celestial time scale.