spacetoday.net: Study: fewer asteroids hit Earth's surface

Posted: Sun, Jul 20, 2003, 12:57 PM ET (1657 GMT)
Asteroid impact illustration (Don Davis/NASA)

Fewer large asteroids will strike the surface of the Earth than previously thought because they will instead break up in the atmosphere, according to a new study. In a paper published in the latest issue of the journal Nature, English and Russian scientists reported on a new computer model that drastically reduces the number of large asteroids that would strike the surface. According to their model, asteroids 200 meters in diameter and larger strike the surface once every 160,000 years, rather than once every 2,500 years that previous studies have concluded. The difference is that a far larger number of asteroids break up in the Earth's atmosphere; these still would have destructive effects, but would not generate effects like tsunamis.