One thing which irritates the dickens out of me is when scientists discuss what to do with an asteroid heading towards Earth, they always immediately dismiss the idea of an atomic bomb, saying it would just make it worse.
It seems obvious to me that an atomic blast would blow it to millions of pieces. Some (most?) would take off in different directions eliminating those parts from the trajectory. Also the tiny bits remaining would have thousands of times the surface area as the original meteor. That would cause them to burn up in the atmosphere, leaving a tiny remnant that would get through.
Why do they dismiss such an obvious solution, making clearly wrong observations?
Probably more of a fear of nukes than anything else.