Selecting the right spot to smash a spacecraft into the surface of a hazardous asteroid to deflect it must be done with great care, according to new research presented at the EPSC-DPS2025 Joint Meeting in Helsinki. Slamming into its surface indiscriminately runs the risk of knocking the asteroid through a “gravitational keyhole” that sends it back around to hit Earth at a later date.
Beware of the ‘gravitational keyhole’: How to find the safest spots to deflect a hazardous asteroid
