Question: If a meteorite has a collision course with Earth, would it be possible to destroy it (maybe with a nucleur missile, if the pros of that outweigh the radiation made?) or would we just be sitting ducks?

Drew Rae answered on 22 Jun 2011:

Hi Robina. Believe it or not, people have put a lot of thought into this. The problem is that you can’t just destroy the meteor. Blasting it into lots of pieces just means you get hit by the same mass of meteor. Even when they burn up in the atmosphere, the energy is still being transferred to the earth. There is a strong argument that it would be better to have a single collision than lots of small bits burning up.

To save the earth, you need to actually divert the meteor so it doesn’t hit at all. For that, you want to start while it is further out, and use a series of small carefully controlled explosions. That’s a much harder mission.

Radiation isn’t a problem, since the explosions will need to happen outside of low-earth orbit to do any good anyway.

(Useful trivia fact: They are called meteors until they hit the ground, then they are meteorites. Think of them being smaller by the time they hit to remember).