NASA: No asteroid collision threat in 2040

The latest calculations indicate a huge asteroid careening toward the solar system won\'t pose a threat to Earth, the U.S. space agency NASA said. Astronomers in Hawaii have downgraded the chances the 460-foot rock -- known as 2011 AG5 -- will strike the planet in 2040 from less than 1 percent to officially zero. \"An analysis of the new data conducted by NASA\'s Near-Earth Object Program Office at the Jet Propulsion Laboratory ... shows that the risk of collision in 2040 has been eliminated,\" NASA said Friday in a written statement. The new assessment was based on new observations of 2011 AG5 made in October, and reduced the uncertainty by a factor of 60. The astronomers have concluded the asteroid will slide across Earth\'s orbit in 2040 with a good 553,000 miles to spare, which NASA said was twice the distance between Earth and the moon. A collision would release about 100 megatons of energy, the equivalent of several thousand atomic bombs, CNN reported.