Dave Hyland, professor of physics and astronomy and also a faculty member in the aerospace engineering department at Texas A&M also a researcher with more than 30 years 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.
What happens is that the paint changes the amount by which the asteroid reflects sunlight. 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. Besides, the kind of paint used is not the kind found at the 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, 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.” explains Hyland.
To most, the concept may sound strange, but the odds are very high that such a plan would be successful and be relatively inexpensive. The science behind the theory is said to be sound therefore NASA has approached Hyland for developing such a project to test the theory.
The smaller asteroids are not discovered as soon as others but they could still cause a lot of damage should they hit Earth. It is really important for our long-term survival that we concentrate much more effort on discovering and tracking asteroids, and developing as many useful technologies as possible for deflecting them.