Unless you were taking a sabbatical from electronic media last week, or decided to catch up on all the seasons of Dexter in one mad marathon, you know that a 17-meter-wide asteroid exploded over Russia, leaving more than a thousand people injured, mostly from the fragments of windows shattered by the sonic boom. The cleanup was expected to require about twenty thousand workers. The same day saw the asteroid 2012 DA14 fly past the Earth close enough to be inside the orbit of communications satellites, but that asteroid had been tracked and scientists knew it wouldn’t hit us. So why didn’t they know about the meteorite over Russia?
In the vastness of space, pieces of rock that size are too small, too dark, and too fast to be easily seen. It takes a lot of observation time with specialized equipment to spot them, and there could be millions of them.
Scientific American has a great article about the efforts underway to catalogue Near Earth Objects (NEO’s) here and good information about the Russian meteorite here, so I won’t repeat it. But even with those efforts, we won’t have a track on every potentially dangerous object out there anytime soon, and it will be even longer before we can do anything to prevent a serious strike (if ever).
What could we do about them? That’s where science fiction thinking comes in.
Giant laser platforms. Nuclear missiles. Gravity rays. Dozens of ideas have been tossed out over the years—some intended to be practical, others just to serve as plots for movies like Armageddon. My own thought is that we should kill two birds with one stone: develop a system that will sweep up the space debris for safety reasons, but then use it for something worthwhile. Perhaps an electromagnetic scoop system or shield that will absorb and utilize or even distribute the huge kinetic energy these things represent (travelling at speeds of nearly twenty kilometers per second) and then make use of their raw materials in the construction of space platforms, colonies, and spacecraft. Many asteroids have significant metal content, and getting metals from the surface of the Earth into space is terribly costly in energy. Far better if the stuff we need is already up there.
I’m not saying it’ll be easy to engineer something like this, but if we ever do we just might find ourselves wishing for more space rubble out there. Deep Impact? Bring it on!