What would we do if we spotted a hazardous asteroid on a collision course with Earth? Could we deflect it safely to prevent the impact?
What would we do if we spotted a hazardous asteroid on a collision course with Earth? Could we deflect it safely to prevent the impact?
Last year, NASA’s Double Asteroid Redirection Test (DART) mission tried to find out whether a „kinetic impactor“ could do the job: smashing a 600kg spacecraft the size of a fridge into an asteroid the size of an Aussie Rules football field.
Early results from this first real-world test of our potential planetary defense systems looked promising. However, it’s only now that the first scientific results are being published: five papers in Nature have recreated the impact, and analyzed how it changed the asteroid’s momentum and orbit, while two studies investigate the debris knocked off by the impact.
The conclusion: „kinetic impactor technology is a viable technique to potentially defend Earth if necessary“.
Our solar system is full of debris, left over from the early days of planet formation. Today, some 31,360 asteroids are known to loiter around Earth’s neighborhood.
Although we have tabs on most of the big, kilometer-sized ones that could wipe out humanity if they hit Earth, most of the smaller ones go undetected.
Just over ten years ago, an 18-meter asteroid exploded in our atmosphere over Chelyabinsk, Russia. The shockwave smashed thousands of windows, wreaking havoc and injuring some 1,500 people.
A 150-meter asteroid like Dimorphos wouldn’t wipe out civilization, but it could cause mass casualties and regional devastation. However, these smaller space rocks are harder to find: we think we have only spotted around 40% of them so far.
Suppose we did spy an asteroid of this scale on a collision course with Earth. Could we nudge it in a different direction, steering it away from disaster?
Hitting an asteroid with enough force to change its orbit is theoretically possible, but can it actually be done? That’s what the DART mission set out to determine.
