What if you put a big enough bomb inside the planet? If you were to do something like that to Earth, wouldn't it crack like an egg?
I'm starting to think that "For Science" is a perfectly valid reason for destroying the Earth.
Well if you want to utterly destroy the Earth,
here's the Wikipedia page with info on the required energy to send every particle of the planet to escape velocity relative (i.e. vaporize the planet). The value it gives for the earth is 2.24 x 10
32 joules, or the Sun's entire energy output for a week or two.
If you just want to crack the earth, that's still a major undertaking since much of the interior is liquid or malleable and pressurized and it would likely cave in again afterwards. Exploding the Earth might be more doable. If you just want to split it in two and move the halves at some reasonable speed away from each other (like, say, 5000 m/s?) I get a required energy of
3.73x1031 joules (according to
this table, enough to turn the Earth into an asteroid belt with energy left over). Even for a slow speed like 100 m/s (which should cause the pieces to collide again after about 20 seconds) it would take 1.49x10
28 joules (calculated from (1/2)mv
2), which is (according to the same site) about half the energy needed to melt the entire surface. This is about 100 seconds of the Sun's entire energy output.
Could you break the Earth in half? Theoretically yes. In practice you need a LOT of dakka.