blackaeronaut Wrote:Nontheless, it still is pretty cool. We've got a freakin' nuclear reactor for a planetary core! It puts a whole new spin on Geothermal Power, don't it?Actually, no. We've known this was almost certainly the case to some degree since sometime in the early fourties.
That they are finding actual evidence of it now is, in fact, pretty cool, but honestly, the idea is a concequence of well established physics and may have been proposed earlier than that.
Radioisotopes on average are pretty dratted heavy. Like Iron, they tend to sink in molten solutions. Usually, they're heavier than iron, which means they sink in molten iron solutions too. The rest of the planet is pretty heavy in it's own right. It pushes down on the things that are sinking. This puts a lot of radioactive stuff in (relitive) close proximity to itself, which, minus a lot of details no one but a fission engineer would care about, is how neuclear reactors work.