NASA did the maths. If you bomb it to gravel, you end up setting the sky on fire basically.
A bomb at short range option only works if you can make a substantial proportion of the resulting gravel miss the planet... which is kind of the whole point anyway... or if you use a big enough nuke to vaporise a substantial percentage of the mass, which then dissipates into space due to thermal effects. (hot gas expands, imparting delta V in random directions etc.)
Although...what debris is left on a reentry trajectory is now very radioactive...
Re: Well ...
NASA did the maths. If you bomb it to gravel, you end up setting the sky on fire basically.
A bomb at short range option only works if you can make a substantial proportion of the resulting gravel miss the planet... which is kind of the whole point anyway... or if you use a big enough nuke to vaporise a substantial percentage of the mass, which then dissipates into space due to thermal effects. (hot gas expands, imparting delta V in random directions etc.)
Although...what debris is left on a reentry trajectory is now very radioactive...