Many proposed anti-asteroid solutions involve knocking them off-course, which carries its own problems — what if you create a fragment that hits Earth regardless? Researchers might have a safer solution. They’ve proposed a system (spotted by Parabolic Arc) that would tether a threatening asteroid to a smaller rock, throwing off the larger body’s center of mass and steering it away from our homeworld. As the method only involves a giant cable, it wouldn’t risk cracking an object into pieces.
The scientists couldn’t test this in real life, of course, so they used a simulated version of Bennu to see how well their idea would work. It’s viable for protecting the planet in a range of conditions, the team said.
There are catches. You need a small asteroid in the first place, of course. Moreover, this requires considerably more time to implement than smacking an asteroid with a spacecraft or projectile. It would work well with a coordinated detection and response system, but might take too much time if observers are caught off-guard. It’s another tool in the arsenal, though, and it may be necessary when it’s likely just a matter of when an asteroid enters a collision course, not if.