Is There a Cluster in the Sky?

It's a huge mystery, or at least a very large one. We can't an why it's there, but we think that it is there. And so that's exciting, because it tells us that something could be going on in the early universe that we don't understand. You know, it's the kind of thing where maybe there's some new physics that explains how things that are so far away from each other in the universe were somehow connected.