Planetary defense test deflected an asteroid but unleashed a boulder swarm

UCLA-led study of NASA’s DART mission determines that the strategy presents previously unanticipated risks

Unanticipated? Really? It was the very first thing that crossed my mind when I heard about DART - what happens to all the bits that break off?

Maybe I should give NASA a call... ;-)

I knew this from playing Asteroids on my Commodore 64. I don’t believe that they hadn’t considered it.

So by all means correct me if I'm wrong, but is this really that bad?

Like, people always freak out about "turning one falling object into many" because they would still share the same collective kinetic energy, but smaller objects are far more likely to burn up high in the atmosphere rather than penetrate for a destructive impact.

The article describes 37 boulders, each with a ~15kT kinetic energy. We have record of meteor events in this magnitude, and they aren't terribly destructive. Nor is it more than a footnote in terms of Earth's daily total energy budget; the Earth isn't going to be cooked by a meteor-swarm of this scale.

It'd seem to me that the biggest risk would actually be peppering Earth's orbital region with far smaller objects that could still damage satellites, no?