Science / Scientists propose tethering asteroids to smaller body to protect Earth

A paper published in EPJ Special Topics has suggested using a tether-assisted system to prevent potentially hazardous asteroids (PHAs)  from hitting Earth. It suggested connecting the threatening PHA to another smaller asteroid, thus changing the centre of mass of the two and hopefully raising PHA to a safer orbit. Researchers used a simulated version of 'Bennu' to check its viability.

Engadget : Jun 22, 2020, 07:16 PM
Science Desk: 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.