Researchers Downgrade Threat of Asteroid-Earth Collision

The number of asteroids capable of colliding with the Earth and causing massive devastation is only about half of previous estimates, according to Yale researchers. Astronomer David Rabinowitz and his colleagues report in today’s Nature that there are only 500 to 1,000 asteroids large enough to cause a catastrophe--rather than 1,000 to 2,000--and say that 90% of them will probably be detected in the next 20 years.

The Rabinowitz team based its estimates on the results of the Near-Earth Asteroid Tracking program. Scientists believe that an asteroid could hit the Earth in the far distant future--sometime over the next 100,000 years--but that in the next 100 years there is only a very small chance.