© Dan Durda/IAAA
The asteroid, 99942 Apophis to give it its full title, is a 46 million tonne, 1,600-foot-wide chunk of space rock that's currently hurtling its way towards our planet. In 2029 it will soar safely past Earth, but we won't be out of the woods just yet.
There's a possibility that it will pass through a slim gravitational keyhole - a tiny, 600 mile area of space - that would cause the asteroid to turn back on itself and strike Earth some seven years later in 2036.
Read the full article on Wired.com.
Do they have few miillions of those satellites, to be sure every piece of comet gets one?