There aren’t many things scarier than a large incoming asteroid. A recent study has uncovered 26 nuclear-grade asteroid collisions since the year 2000, and any one asteroid could wipe out humanity at any given time. Statistically, it probably won’t—because it hasn’t—but the scale of this threat is massive. And we’re completely helpless in the face of it, right?
Actually, not so much. We’ve already learned how to non-invasively intercept asteroids, and we’re perhaps 20 or 30 years away from never having to worry about another asteroid collision again. Last week, NASA announced the selection of 18 proposals for viable technology that can be used to collect or redirect asteroids within the near future. Among these are four proposals to break material off of larger asteroids, altering their trajectory—and a specific mission to actually do this to a small asteroid by 2021, putting an asteroid of up to 30m (98 feet) in diameter into a harmless lunar orbit for future study.
If you want to hear more details, NASA has prepared a two-hour streaming TV special about its new asteroid initiative:
NASA has already worked for several years on designs for a Hypervelocity Asteroid Intercept Vehicle (HAIV) that would nuke incoming asteroids from orbit (it’s the only way to be sure), but these kinds of asteroid disruption and redirection technologies haven’t been developed beyond the planning stage. After the 2020 mission, we will have successfully redirected one asteroid and we’ll be well on our way to knowing what we will need to do in order to redirect more.
Actually locating these asteroids in time to do something about them is, of course, also necessary. NASA is crowdsourcing that problem with the Asteroid Grand Challenge.