Another disaster waiting to happen

I think I linked to an article on this a while ago, but it seems like it bears repeating. My question is: If we know the rock is a major disaster waiting to happen, and could happen at any time, why don't we blow it up? Or do something along those lines? I don't know a lot about this sort of thing, but it seems to me it would be pretty easy to get rid of the threat now. That's one proactive national defense initiative I would get behind.