Posted: Sat, Oct 12, 2002, 8:29 AM ET (1229 GMT)
Small asteroids are less numerous and thus less likely to collide with the Earth than previously thought, according to a new study. The research, reported this week by Alan Harris of the Space Science Institute, concluded that there are about 500,000 near-Earth asteroids about 50-75 meters across. This means that, on average, one such small asteroid will collide with the Earth every 1,000 years; previously, astronomers thought one such impact took place every 100 years. Such impacts are similar in size to the Tunguska explosion in Siberia in 1908. Harris noted that while the odds of an impact are reduced, impacts are random events and can take place at any time, just less frequently than once thought.

Related Links:

•  SPACE.com article