WASHINGTON, DC – One weighty decision that the world will need to make in 2010 is whether to support an idea raised by Anatoly Perminov, the head of the Russian space agency Roscosmos, to launch an unmanned mission to redirect a large asteroid that might collide with Earth after 2030.
At more than 360 meters in diameter, the asteroid, Apophis, is a dozen times larger than the Tunguska space object (presumably a meteorite or comet) that devastated a large part of eastern Siberia a century ago. As far as can be determined, that object detonated on June 30, 1908, with the power of a nuclear weapon, felling 80 million trees over a 2,000-square-kilometer area.
According to NASA, if Apophis hit the Earth, it could release more than 100,000 times the energy of the Tunguska event. Thousands of square kilometers could vaporize in the blast, but the whole Earth would suffer from the loss of sunlight and other effects of the dust released into the atmosphere. This danger explains why a Russian analyst has called Apophis a “space terrorist.”
Current projections are that Apophis, which was discovered in 2004, will orbit near the earth several times between 2029 and 2036. In October 2009, near-Earth object (NEO) trackers Steve Chesley and Paul Chodas of NASA's Jet Propulsion Laboratory in Pasadena, California, placed the odds of Apophis striking Earth in 2036 at about one in 233,000, lower than previous estimates.