The going theory about smashing a nuclear missile onto an on-coming asteroid is that the big BOOM wouldn’t be enough, at least according to Billy Bob Thornton in Armageddon. Researchers are now claiming that it may be enough.
Even though NASA and other space agencies have most of the nearby asteroids mapped—key word there being most—the possibility of one heading straight for us is something worth preparing for. After all, even with all of our advanced space imaging, the occasional rock still ends up surprising us. And asteroid surprises are not good surprises. So, yes, let's consider nuking the damn thing.
Luckily, the bright radioactive minds at Los Alamos National Laboratory are looking for a definitive answer to that. Right now, they're using a 32,000-processor rig to simulate a nuclear attack against an incoming asteroid. Above, a one megaton "nuclear energy source" (warhead) hits the Itokawa asteroid—half a kilometer wide. And good news! The blast and subsequent shockwave would be enough to "mitigate" the rock's threat to our tiny planet. Which means it wouldn't kill us all, right? Why don't we bump it up to two megatons, gents.
The real question here is why hasn’t NASA developed the technology to create a Green Lantern power ring and use it to catapult the asteroid over the moon? There is a definite certainty that there is someone named John Stewart more than willing to step forward and wear that ring.