Friday, August 14, 2009

Nasa Does Not Have Enough Money To Spot Incoming Asteroids As They Plummet Towards Earth

Congress assigned the space agency four years ago to watch 90 per cent of potentially deadly rocks hurtling through space by 2020 but never gave it the money to build the necessary telescopes, according to a report by the National Academy of Sciences. The agency estimates that about 20,000 asteroids and comets in Earth's solar system bigger than 460 feet in diameter are potential threats to the planet. Rocks between 460 feet and 3,280 feet in diameter can devastate an entire region Lindley Johnson, NASA's manager of the near-Earth objects program, said. So far, scientists know the whereabouts of about 6,000. Last month, astronomers were surprised when an object of unknown size and origin bashed into Jupiter and created an Earth-sized bruise that still is spreading. Jupiter gets hit more often than Earth because of its immense gravity, enormous size and location.Movies such as Armageddon and near misses in previous years have alerted people to the seriousness of falling asteroids. However, the academy concluded that there had been "relatively little effort" by the US government to addressing the threat. NASA calculated that to spot the asteroids as required by law would cost about $800 million (£483m) between now and 2020, either with a new ground-based telescope or a space observation system. At the moment, NASA has identified about five near-Earth objects that pose greater than a one-in-a-million risk of hitting the planet and being big enough to cause serious damage. Astronomers are watching a 430-feet diameter rock that has a 1-in-3,000 chance of hitting Earth in 2048 and a much-talked about asteroid, Apophis, which is twice that size and has a 1-in-43,000 chance of hitting in 2036, 2037 or 2069.