Spray Painting Asteroids Could Protect Earth from Space Rock Threat, Say Scientists
Recent Earth-scorching encounters with asteroids have accelerated the search for ways to protect our planet from collisions with space rocks. Now, scientists think they may have hit on a answer — paint.
But lets recap first. On February 15, asteroid 2012 DA14 redefined the words close shave after it missed Earth by a mere 17,200 miles. Just hours earlier, a meteorite exploded over the Russian city of Chelyabinsk, damaging buildings and injuring 1,200 people.
In addition, residents in California reported seeing an unusual flash of light over the San Francisco Bay area on February 16, followed a day later by a meteor shower in Florida.
Space.com reports the heightened cosmic activity has increased scientists’ resolve to find viable solutions to reduce or deter inevitable destructive impacts in the future.
Dave Hyland, professor of physics and astronomy, and faculty member in the aerospace engineering department at Texas A&M University, and a researcher with more than 30 years of awards to his name, believes he has found one of those solutions.
Hyland’s idea builds on an earlier proposal that possibly threatening asteroids could be dusted with a thin coat of paint using a process called “tribocharging powder dispensing.”
This process entails spreading a thin layer of paint on an approaching asteroid. But, of course, it’s not your average house decorating paint.
“It could not be a water-based or oil-based paint because it would probably explode within seconds of it entering space.”
“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.”
“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.”
The thinking behind the theory is that the paint changes the amount by which the asteroid reflects sunlight, potentially moving it away from Earth through the “push” arising from the thermal photons radiating from the asteroid’s surface, Science Daily reports.
That ‘push’ effect is called the Yarkovski effect (discovered by and named for a Russian engineer in 1902).
The force is created because on a spinning asteroid the dusk side is warmer than the dawn side and emits more thermal photons. Each of these photons carries a small momentum. The unequal heating of the asteroid then creates a net force strong enough to cause the asteroid to shift from its current orbit, Hyland theorizes.
So how would scientists get paint on the asteroid in the first place?
The mechanics were such an enterprise were discovered by a former student of Hyland’s, Shen Ge, who has since started a new space company.
The “tribocharging powder dispenser” would spray a mixture of inert gas and charged dry-paint powder at the asteroid that would pull 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.
NASA has now approached Hyland to discuss developing such a space test, and according to Science Daily — the Earth may need it soon.
An asteroid called Apophis is due in 2029 and will come nearer to the planet than many of the communications satellites in orbit right now. It will fly by on April 13 and make a return trip in 2036.
It’s estimated to be more than 1,000 feet in length and is somewhat fittingly named after an Egyptian god of chaos and destruction. Apparently there is no chance of it hitting Earth in 2029, but a small chance exists in 2036, says Hyland.
The paint theory is not the only asteroid deflecting plan in town, but as Hyland astutely observes, the more options scientists have at their disposal the better.
“It is really important for our long-term survival that we concentrate much more effort discovering and tracking them, and developing as many useful technologies as possible for deflecting them,” he said.
