Astronomers have found what looks very much like a pair of supermassive black holes that are orbiting each other in a binary pair. This is a rare beast, but what makes this even more amazing is that, if they're right, these two monsters are doomed to spiral together and merge in as little as ten thousand years!
If this is the case, these black holes are the tightest pair like them ever seen, and will merge far sooner than any other known system.