What to do about Earth-threatening space rocks? Credit: Texas A&M
If an asteroid has Earth’s name on it, how best to deflect such an incoming menace?
A spurt of special spray paint is the possible answer from Dave Hyland, professor of physics and astronomy and also a faculty member in the aerospace engineering department at Texas A&M.
NASA has approached Hyland for developing such a project to test the theory.
At the heart of the concept is a process called “tribocharging powder dispensing” – as in high pressured – and spreading a thin layer of paint on an approaching asteroid.
Once applied to the space rock, the paint spray would change the amount by which the asteroid reflects sunlight, Hyland theorizes. That would produce a change in what is called the Yarkovski effect – an effect which was discovered by a Russian engineer in 1902.
The Yarkovski force arises because on a spinning asteroid, the dusk side is warmer than the dawn side and emits more thermal photons, with each photon carrying a small momentum.
The unequal heating of the asteroid results in a net force strong enough to cause the asteroid to shift from its current orbit, Hyland further theorizes.
By the way, the kind of paint used is not the type you can find and buy at your local hardware store.
“It could not be a water-based or oil-based paint because it would probably explode within seconds of it entering space,” Hyland notes.
But a powdered form of paint, Hyland added, could be used to dust the asteroid and the Sun would then do the rest. It cures the paint to give a smooth coating, and would change the unequal heating of the asteroid so that it would be forced off its current path and placed on either a higher or lower orbit, thus missing Earth.
“I have to admit the concept does sound strange,” Hyland said in a press statement, “but the odds are very high that such a plan would be successful and would be relatively inexpensive. The science behind the theory is sound. We need to test it in space.”
NOTE: Check out a video that illustrates this asteroid deflecting idea. Go to:
http://tamutimes.tamu.edu/2013/02/21/asteroids-no-match-for-paint-gun-says-prof/
By Leonard David