The sky is falling. Eventually. Count on it.

At some point in time Earth will get smacked again by a chunk of rock wandering through the solar system. That's a given, and it actually happens several times a year. But probability says with near-certainty that a big'un will intersect with Mother Earth. There are some projects gearing up to look out there, but as early warning systems they are far from comprehensive.

And what if we actually do see something ahead of time? Just what would we do? Face it, Bruce Willis isn't getting any younger.

Fortunately, we've got some very intelligent people thinking ahead and more importantly, doing something about it.