“In general,” he added, “What I don’t like is … the idea that kiloton or a megaton is just an energy unit, that it’s equivalent to so many joules or something. Because you could do that. You could claim that your house runs so many tons of TNT worth of electricity per year, but it sort of trivializes the notion.”
While I agree that the notion of comparing a bolide explosion to a nuclear event is misleading, I think he misses the boat himself here. It’s not just about an “energy release.” It’s about how fast the energy is released. That is, talking about megatons of TNT is a discussion about power, not energy per se. This is the same confusion that people have with regard to rocketry. They often talk about how much “energy” it takes to get into orbit, when in fact it’s not much more energy than it takes for intercontinental aircraft flight. The difference is that the airplane deploys its energy over many hours, whereas the rocket must do so in a very few minutes. When the Shuttle took off, it generated more power than the entire nation’s electrical grid for the first two minutes. In fact, when I was working propulsion at Rotary Rocket in the nineties, we used to joke about what units we should use to describe the power output of the engine, and thought that “Hoovers” (as in the dam) would be a useful one.
In any event, radiation and heat or no, either exploding meteoroids or nuclear weapons city busters, and events to be concerned about.