Are we in danger?
Asteroids have been the fodder for some… interesting science fiction blockbusters, but with the strike in Chelyabinsk, Russia this year, scientists say it's time to get serious. Two papers published in Nature -- one of the most prestigious academic journals -- suggest that asteroid strikes might be a bit more common in the coming years.
Current searches for asteroids are only for those that are at least 1 kilometer wide, but those are rocks big enough to end our civilization. Smaller bits -- those that are capable of devastating countries or cities -- slip through the cracks.
Former astronaut Edward Lu is prepared to help defend Earth with B612 -- a project with the goal of detecting much smaller threats from outer space. According to the project, there are a million "near-Earth asteroids large enough to substantially damage or destroy a major city." Equivalent to a massive minefield of nuclear warheads, this is not a threat we can simply ignore.
Impacts the size of the one that hit Chelyabinsk should be expected every one or two decades. To be sure, a good chunk of the Earth is uninhabited, and it's unlikely that any of these impacts will hit a major city, but with the stakes as high as they are, that's no longer a gamble we can afford to make.