Threats from Space A Review of U.S. Government Efforts to Track and Mitigate Asteroids and Meteors (Part I & Part II)

On Friday, February 15,2013, two events occurred that received worldwide attention. An unforeseen meteor (estimated 50 feet in diameter) exploded in the sky above the Russian city of Chclyabinsk releasing the equivalent of a 300 kiloton bomb, about twenty times the explosive energy of the atomic blast used over the city of Hiroshima. This blast injured nearly 1,200 people and resulted in an estimated $33 million in property damage. On the same day, a small asteroid (150 feet in diameter) discovered by amateur astronomers and tracked closely by NASA passed safely by the Earth, but within the orbital belt of geostationary satellites. Until it entered our atmosphere, the Russian meteor went completely undetected. According to NASA, the two events were unrelated, but raised public awareness of the potential threat from Near Earth Objects (NEOs). NASA believes it has discovered 93 percent of the largest asteroids in near-Earth orbit, those 1 kilometer or larger, but what about the other seven percent remaining, about 70, or even those smaller than 1 kilometer, estimated to be in the thousands? An asteroid as small as 100 meters could destroy an entire city upon a direct hit. The two events of Friday, February 15, the harmless flyby of asteroid 2012 DA14 and the not-so-harmless impact of a meteor in Russia, are a stark reminder of the need to invest in space science. What are the U.S. government's plans and programs to track, classify, and mitigate the threat of NEOs?