Splat! How paintball could save the Earth

Graduate’s unorthodox plan to deflect asteroid wins prize

Saving the human race from the threat of an intergalactic asteroid could fall to that staple of office bonding trips and laddish weekends – paintballing.

While blockbuster disaster films have already envisioned an “extinction-level event” where life on earth is under threat from an asteroid, scientists in the US have also been giving the matter considerable thought.

Sung Wook Paek, a graduate student at the Department of Aeronautics and Astronautics at MIT in Cambridge, Massachusetts, has now won a competition to solve the problem.

The so-called “move an asteroid 2012” competition was sponsored by the United Nations Space Generation Advisory Council and aimed to find the best possible solution to deflect asteroids or other near-earth objects.

Mr Paek’s intergalactic paintball strategy would see paint pellets fired at an asteroid, covering it in a fine, five-micrometer layer of paint. This would then take advantage of solar radiation pressure – the force exerted on objects by the sun’s photons – to deviate it from an earth bound trajectory.

Just as black paint absorbs solar radiation, a layer of white paint would reflect the solar radiation and push it off course.

But the plan’s fault may lie in its lack of speed –it could take up to 20 years for the effect of solar radiation to pull the asteroid off its path.

The proposal is based on the 27-gigaton rock “Apophis” which could come close to Earth in 2029 and again in 2036. The asteroid has a diameter of 1,480ft and would require five tons of paint to cover it.

The pellets would have to be made in space on the International Space Station due to the danger of them fracturing on take-off from Earth.

Far-fetched Hollywood solutions to the problem have included landing on an asteroid, drilling into its heart, and blowing it up with nuclear weapons. Another NASA alternative is the “kinetic interceptor” which could deflect an asteroid by crashing into it.

According to Space.com, a one mile-per-hour impact could divert an asteroid by 170,000miles if hit 20 years before the predicted collision.

“It is very important that we develop and test a few deflection techniques sufficiently so that we know we have a viable ‘toolbox’ of deflection capabilities to implement when we inevitably discover an asteroid on an impact trajectory,” said Lindley Johnson, programme manager for NASA’s Near Earth Observation Programme.

Asteroid DA14, which is roughly the size of a city block, will be among the closest to fly by Earth when it passes within 14,000 miles in February.

“These types of analyses are really timely because this is a problem we’ll have basically forever,” warned William Ailor, principle engineer for the Aerospace Corporation in California.