One of the secondary goals of the Fermi gamma ray satellite is to look for the signature of dark matter. One idea for dark matter is that it's composed of weird (and as yet undetected) particles called WIMPs (weakly interacting massive particles). A very odd property about them is that they are self-annihilating: when two of them touch, they turn into energy (and other, more easily detectable particles). When I first read about this several years ago I was pretty excited, because this is finally a testable hypothesis about dark matter.
My fellow Hive Overmind blogger and astronomer Sean Carroll writes that it's possible Fermi has done just this. The data are not conclusive, but very provocative nonetheless. He has the details. But I can't resist adding that on The Big Bang Theory a few weeks ago, Raj and Sheldon were investigating building a detector to look for this very ...
