BellaOnline Forums Education Astronomy Arghhh! Duck! It's Asteroid Day!

Here’s the thing about asteroid strikes that makes them different from many other natural disasters—they are preventable. If we know about an asteroid’s collision course ahead of time, we can nudge the object, changing its course so it whizzes by without hitting us. There are a variety of ideas on how best to do this, ranging from using a nuclear bomb to painting the incoming object white (or black) so photons will push it off track. But the technique that NASA officials say will likely make the most sense, depending on the situation, involves ramming it with a spaceship, similar to what NASA’s Deep Impact mission did to the comet 9P/Tempel in 2005. It’s a process that has to be carefully engineered: you have to know the asteroid’s size, shape, speed, projected orbit, and composition to calculate the effect of the impact.

At this point, Yeomans estimates, we would need 10-20 years of advance notice to prepare—to build a ship, launch it, hit the asteroid, and allow time for the spacecraft’s small nudge to sufficiently skew the object’s trajectory so it misses Earth. “If you find one that’s going to hit tomorrow morning or within three weeks, or even within a few months, there’s not a whole lot you can do about it except evacuate the affected areas,” he says. “The search is the most important.”