You don't actually have to destroy it, all you have to do is give it a nudge. Just flying a space ship next to it might be enough of a gravitational pull to change its orbit just a little bit so that it misses. The key is to find them early enough so you can send the probe. So far they think they've found over 90% of them.
Originally Posted By: KrisZ
Do some of you even realize what exactly we are discussing here, energy wise? It all looks easy and doable in Hollywood movies, but in real life, deflecting an asteroid is nearly impossible. We are talking here about objects traveling at about 40,000 MPH with the kinetic energy at impact ranging from 4 megatons for the little guys to 46,000 megatons and this is at impact, in space these things have a much higher kinetic energy because they would not have been slowed down by the atmosphere. And don't tell me we will use the freaking lasers.