Drog writes "Earth has had a few near misses with asteroids recently (although "near hits" would be more accurate). It's just a matter of time, though, before we detect one with our name on it. In this New York Times article, experts discuss the various ways that we might go about saving our planet. Remarkably, nuclear detonations are not a good option, as they would break the asteroid into many pieces and merely increase our odds of being hit. And a detonation some distance away may simply be absorbed by the asteroid with virtually no effect. Instead, say scientists who study asteroid hazards, a gentle sustained push is what's needed (slow and steady wins the race). Some of the approaches have been discussed in science fiction for years--a mass driver, an electromagnetic machine which hurls dirt from the surface, an orbiting parabolic mirror to heat up the surface and create a plume of vaporized material. All of these methods require one thing, however. Time. At least several decades warning."