Re:The math doesn't look good... (Score 1)

Would it really screw over earth if [the dud nuke] came down, along with all the (I'm assuming here) fallout?

That'd be kinda like you attacking me with a small sledge-hammer and me worrying about you taping a tack to the end.

If a comet-sized rock hit earth, it would probably impart some thousands of gigatons of kinetic energy. If it hit near a nuclear power station, you'd have hundreds of pounds of released high-end radiation. The remains of a nuke would be the least of our problems.