The cosmos put on quite a show yesterday, sending two massive asteroids (one a total surprise) Earth's way within hours of each other.
A good thing, all in all. Nobody died, but the astronomic coincidence -- and especially the stunning dash-cam images out of Chelyabinsk -- focused a lot of minds on a real threat our civilization faces.
First reports were that the meteor breakup released about 10 kilotons of energy, less than either the Hiroshima or Nagasaki blasts, at a height of perhaps 30 kilometres or more. Just powerful enough to scare governments out of their complacency. Reports later in the day, however, were enough to scare me too:
The meteor didn't weigh 10 metric tons, but 7,000. It exploded much closer to the ground than first thought, and with force comparable to many modern nukes. If it had been mostly iron and nickel rather than rock, and/or contacted the atmosphere at a far steeper angle, Chelyabinsk and its million-plus people might have been destroyed. Yesterday!
This is being described as a once-in-a-century event, Tunguska being the other bookend. But for about half that length of time, mutual assured destruction was the military philosophy of the two superpowers. We came close to blundering our way to annihilation during the Cuban missile crisis. Now it turns out we also ran a real chance of a random natural event triggering our death wish.
It isn't getting better. The superpowers today may be a bit less quick on the draw, but imagine a similar meteor hit in North Korea, Israel, anywhere in India or Pakistan. Would military minds wait for scientists to weigh in before rushing to "retaliate?" Maybe, but millions could die instead.
It has always been in our long-term interest to develop the technology to detect and track Earth-grazing asteroids of all sizes, and learn to deflect them if they pose a deadly threat. Now that we've seen how closely they can mimic our own nuclear warheads, we have an even more pressing reason, no?