Planetary defense test deflected an asteroid but unleashed a boulder swarm

Key takeaways

NASA’s DART mission crashed a spacecraft into the nearby asteroid Dimorphos to test a possible strategy for deflecting asteroids that are headed for Earth.

The test succeeded in knocking Dimorphos slightly off course but also dislodged from its surface 37 boulders that are now moving away from the asteroid.

The effort reveals an unintended consequence of technology to deflect asteroids on a collision course with Earth: Smaller rocks flying off into space could create their own problems.