Planetary defense test deflected an asteroid but unleashed a boulder swarm::A UCLA-led study of NASA’s DART mission determined that the strategy presents previously unanticipated risks.
Totally totally totally unanticipated that one. Like every discussion about asteroid defence ever anticipated exactly this kind of scenario.
Was no one involved alive in 1998? We had two movies about this.
No one remembers deep impact
Somehow, I found the lead scientist’s statement and the associated news to be click-baiting. Right, you crash something into a composite rock, and expect no ejecta from it. That’s pretty freaking believable. That’s like, the most basic physics you can expect from it. This is just to grab your attention so we can get more funding (which they may deserve, even if this is irritating), folks.
Why is this a problem?
The point is to deflect asteroids decades or even centuries out. If they do that then the boulders they eject will still be in the same gravitational area and will still move with the parent object. I doubt the force of impact is going to send them on completely new courses. And even if they did it’s unlikely that the new course would be the same as the old course, if anything it would be either the reverse of the old course, or a tangent to it.
Asteroids may be detected very late when they’re already near earth. Breaking up a large rock into a lot of smaller ones may not be a big help. But all of this has been known for a very long time.
