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Article: A little less to worry about from on high.(estimate of the number of large asteroids with orbits that bring them within five million miles of Earth is lowered to 700)(Brief Article)
- Article from:
- U.S. News & World Report
- Article date:
- December 6, 1999
- Author:
CopyrightCOPYRIGHT 1999 All rights reserved. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Barring some sort of human-devised defense measures, astronomers assure us that an asteroid will some day hit Earth hard enough to threaten civilization. Such blows are typically a million or so years apart, so the risk to mankind is low. But in a sharp revision of this prediction, two new independent analyses conclude that there may not be quite as many planet-busting rocks lurking undetected in our neighborhood as has been feared.
The standard guesstimate has been that 2,000 or more potential doomsday asteroids, those more than one kilometer, or 0.6 mile wide, near Earth's orbit. That size stone, plummeting into the crust at 65,000 miles per hour, experts say, ...