Spray paint could save Earth from giant asteroid impact

Potentially threatening asteroids can be deflected from colliding with Earth using a novel technique - spraying a thin layer of paint on the approaching space rock, experts claim.
According to Dave Hyland, Texas A&M University aerospace and physics professor, the science behind the plan is absolutely rock solid so much so that NASA is getting involved and wants to know much more.
Hyland says one possible way to avert an asteroid collision with Earth is by using a process called "tribocharging powder dispensing" - as in high pressured - and spreading a thin layer of paint on an approaching asteroid, like the one named DA14 that came within 17,000 miles on February 15.

What happens is that the paint changes the amount by which the asteroid reflects sunlight, Hyland theorises, producing a change in what is called the Yarkovski effect - discovered by a Russian engineer in 1902.
The force arises because on a spinning asteroid, the dusk side is warmer than the dawn side and emits more thermal photons, 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 theorises.

"It could not be a water-based or oil-based paint because it would probably explode within seconds of it entering space," Hyland noted.

"But a powdered form of paint could be used to dust on 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," Hyland said in a statement.
"I have to admit the concept does sound strange, 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," he said.

As for getting the paint on the asteroid, the "tribocharging powder dispenser" would spray a mixture of inert gas and charged dry-paint powder at the asteroid that would attract the powder to its surface through electrostatics. Then solar wind and UV radiation would cure the powder, giving a smooth, thin coat on the surface.
Getting the paint in the asteroid's path in a timely manner will certainly be a challenge, Hyland observed.
NASA has approached Hyland for developing such a project to test the theory, as an asteroid called Apophis is due on April 13, 2029 and will come closer than many communications satellites in orbit right now.

There is no chance of its hitting Earth in 2029, but a small chance in the next close approach in 2036, Hyland noted.