Comment Re:Start with Venus... (Score 1) 319
The first nuclear bomb test heated a volume of atmosphere to higher temperatures, and reached higher pressures, than any similar volume of atmosphere in the entirety of Earth's history, by natural or artificial means.
What about a meteorite impact? The shockwave from a sufficiently large one (and there is plenty of evidence of these) would presumably be very similar to that of a nuclear device. While the energy density at the core of the explosion might be less than a nuclear bomb presumably it is the shockwave heating which you need to generate the chain reaction since this will create high temperature and pressures rather than just temperature? I'm not a plasma physicist though...