The next time a large object falls out of the sky, we may be taken by surprise―currently, there is no early warning system for near-earth objects. However, over the next decade, sky surveys, like the one being done by tholen, should begin filling that gap. Astronomer are compiling a list of thousands of asteroids to help us anticipate the next strike. Every couple of weeks, says former astronaut Lu, we’re going to be finding another asteroid with, like, a one-in-a-thousand chance of hitting the earth.