Weaver, a scientist at Los Alamos National Laboratory (LANL), doesn’t hunt for killer asteroids, but he does study the ways humans might use their vast nuclear arsenals–designed to wipe each other off the face of the planet–to save the whole of humanity from a catastrophic asteroid impact. Weaver has been running simulations on LANL’s Cielo supercomputer to determine humanity’s capacity to mitigate an impending asteroid threat using a one-megaton nuclear energy source–one roughly 50 times more powerful than the blasts inflicted upon Hiroshima and Nagasaki at the close of World War II.
There’s more than one way to divert an asteroid of course. With the proper notice, like that afforded us by the asteroid Apophis or 2011 AG5, humans could fly a spacecraft out to intercept an asteroid in deep space. This spacecraft could impact the asteroid to nudge it slightly off course, or it could fly abreast of the threat, acting as a kind of “gravity tractor” whose slight gravitational tug would push it off its collision course over time. It’s even been suggested that a spacecraft could bombard one side of a killer asteroid with a laser, heating it enough to change its orbital characteristics and its path.
That’s if we have time. “From my perspective, the nuclear option is for the surprise asteroid or comet that we haven’t seen before, one that basically comes out of nowhere and we have just a few months to respond to it,” Weaver says. In other words, lacking the time to deploy something more elegant, we can pull out the method of last resort and blast the threat out of existence with the biggest energy source at our disposal. There’s no telling exactly how an asteroid deflection mission would transpire because it’s never been tried before, but scientists like Weaver are hard at work simulating the ins and outs of mitigating of an incoming impactor. It’s knowledge we hope we’ll never have to use, but should we ever have to, this is how it would work.