In the 1960s, the Rolling Stones sang that we should “Paint It Black.” The Stones may be one of the world’s great rock bands, but they don’t know anything about deflecting asteroids. If they had named the song “Paint It White,” they may have been on to something.
Sung Wook Paek, a graduate student at the Massachusetts Institute of Technology, won the 2012 Move an Asteroid Technical Competition held by the United Nations’ Space Generation Advisory Council. He offers a novel idea for diverting the next killer asteroid that hurtles our way.
An asteroid is too big to destroy with nuclear weapons without shattering it into thousands of fragments that would endanger Earth. Mr. Paek has devised a less-violent solution: Cover the surface of the asteroid with reflective white paint delivered by clouds of solid pellets.
Solar radiation pressure would exert a force on the asteroid’s newly reflective surface. That would gently nudge it out of an Earth-bound trajectory.
Mr. Paek tested his theory by running simulations on the asteroid Apophis, a 27-gigaton monster that will fly by Earth in 2029 and 2036. By his calculations, it will require a mere five tons of paint, delivered in two rounds of white pellets, to cover the spinning asteroid.
It won’t be the prettiest paint job in the universe. But it will deflect Apophis from its trajectory after 20 years of solar radiation pressure and drag.
Scientists are intrigued by the logic and elegance of the theory. It would require split-second timing and international cooperation, but it could be done.
In theory, humans would have a few decades before a threatened impact to refine the idea further. But it is already more promising than the expected blowback from a nuclear strike.
Mick Jagger and Keith Richards probably wouldn’t mind the irony of painting the rolling stones headed our way white. When you’re saving the planet, you can’t always get what you want.