Energy to blow apart a planet?

His Divine Shadow · Post by **His Divine Shadow** » 2002-10-17 05:47pm

Using wongs asteroid destruction calculator I found out that it would take 8e27joules to fragment a planet the size of earth, is that really plausible? What sort of fragmentation are we looking at?

The fragments accelerating away from each other or a bunch of fragments that'll soon reform as a planet again?

Secondly, how much energy would it take to say blow a planet apart in two or ten pieces or anything inbetween, not at escape velocity though, but so that they are moving apart from each other.

I ask this because there are apparently many ways of shattering a planet without automatically overcoming it's gravitational binding energy.

His Divine Shadow · Post by **His Divine Shadow** » 2002-10-17 07:38pm

Note, we could take what happened in Moo2 when a planet is hit with a stellar converter as an example too, that is a planet broken up in a few pieces.

Captain Hornblower · Post by **Captain Hornblower** » 2002-10-17 07:47pm

A planet fragmented will re-coalesce unless sufficent energy to overcome the gravitational binding energy is introduced. This energy is going to be significantly (many orders of magnitude higher) higher than the energy required to "fracture" an earth sized planet.

His Divine Shadow · Post by **His Divine Shadow** » 2002-10-18 07:24am

Captain Hornblower wrote:A planet fragmented will re-coalesce unless sufficent energy to overcome the gravitational binding energy is introduced. This energy is going to be significantly (many orders of magnitude higher) higher than the energy required to "fracture" an earth sized planet.

Yes well I didn't mean that one would actually have to blow it apart to such a degree that it wouldn't re-coalesce, just wondering how much energy it could take to blow it apart without actually having to prevent it from re-forming.