Earth Dodges a Few Hundred Asteroids
(From the March/April 2000 issue of StarDate magazine)
The number of potentially deadly asteroids zipping through our region of the solar system is only half as big as previously thought, according to a report published in the January 13 issue of Nature. Astronomers had estimated the population of near-Earth asteroids at least one kilometer (0.6 mi) in diameter at 1,000 to 2,000. But data gathered by NASA's Near-Earth Asteroid Tracking System (NEAT) indicates there are no more than 500 to 1,000 large near-Earth asteroids. Asteroids are chunks of rock and metal left over from the formation of the solar system. A collision with a large asteroid 65 million years ago may have led to the extinction to the dinosaurs and most other life on Earth. A 1-kilometer asteroid could destroy a city and cause global environmental havoc.
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