Mirror Bees

The Planetary Society, the space advocacy group founded by Carl Sagan among others, has always gone beyond simple advocacy to actually fund research and education projects around the world. No doubt the best known of those projects is the Society's support efforts to find extraterrestrial life, both by searching for radio signals (or perhaps optical signals) and by supporting research into the fundamentals of life with an eye towards establishing some parameters for possible life beyond Earth.

The Society is now tackling the problem of protecting Earth from large asteroid strikes by supporting early research into a concept called "Mirror Bees." It's a simple, elegant idea. Under it, if we found a dangerous body on a collision course with Earth decades, or at least many years before the event, we would dispatch a small fleet of small mirrors to rendezvous with it. The mirrors would be deployed in such a way as to allow them all to focus reflected sunlight on one tiny spot on the asteroid. That intense focus of energy would vaporize that part of the rock. The reaction of that vaporized rock jetting away into space would slowly push the asteroid into a new, harmless orbit. No nuclear bombs, no rockets, just mirrors.

There is still much work to be done on the idea. For instance, maintaining such a tight focus for several years in a dynamic situation would require some truly impressive formation flying of the mirrors. The approach may also work better on some types of bodies than others. Still, it's certainly well worth exploring.