(Sen) - Firing paintballs at an asteroid heading toward Earth could deflect its trajectory away from a collision course, according to an innovative proposal by a student at the Massachusetts Institute of Technology (MIT). The force of being hit by volleys of pellets full of paint would cause an initial shift in the asteroid's trajectory, and once covered in reflective paint the rock would be deflected further off course by the Sun's photons bouncing off its surface.
The proposal comes from Sung Wook Paek, a graduate student in MIT’s Department of Aeronautics and Astronautics. His paper won the 2012 'Move an Asteroid Technical Paper Competition', sponsored by the United Nations Space Generation Advisory Council. Paek presented his paper at the International Astronautical Congress held earlier this month in Naples, Italy.
The competition called for ideas to deflect a near-Earth object such as an asteroid. A large space rock hitting Earth could destroy the planet and scientists are exploring ways to avoid armageddon, a scenario portrayed by the Hollywood blockbuster of the same name. Paek's plan would be for a spacecraft to close in on the rogue asteroid and fire two rounds of paintballs at the rock, the first volley covering its front and the second volley covering its backside in white paint. The pellets would burst apart on impact and cover the asteroid's surface in a fine layer of paint, doubling its reflectivity, or albedo. The initial force from the pellets would bump an asteroid off course, and, over time, the Sun’s photons would deflect the asteroid even more.
Paek's idea builds on last year's competition winning proposal to fire solid pellets at a threatening asteroid. The addition of paint to the mix would provide additional course alteration by the solar radiation.
As a test case for his theoretical study, Paek used the asteroid Apophis, due to fly within 30,000 km of Earth in 2029 and again in 2036. Apophis, which has a diameter of 1480 feet (about 300 metres) would need 5 tonnes of paint fired at it, according to Paek's research. After being covered in paint it would then take an estimated 20 years for the solar radiation pressure to knock the asteroid off course.
Lindley Johnson, of NASA's Near Earth Objects Observation Program, said "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".
Discovered in 2004, Apophis will pass within 29,450 km of Earth in 2029. However, there is some uncertainty about how close it well come on its second encounter in 2036, and Russia announced in April this year they intend to send a probe to the asteroid to try and find out. To be launched in 2015 the radioisotope powered satellite would aim to discover Apophis's exact trajectory.