How NASA's Fermi Telescope Sidestepped a Gigantic Space Crash

There's all kinds of asteroids and other debris cruising through space, but a lot of the really dangerous stuff is stuff we put there ourselves. NASA's cosmic bubble-spotting Fermi telescope almost had an intergalactic fender bender, but not with some epoch-old rock floating through the cosmos. No, it almost got… » 5/02/13 11:16am 5/02/13 11:16am