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Posted at 03:57 PM ET, 09/29/2011

Asteroids that could threaten Earth are 90 percent found, NASA says


Illustration of the large asteroid that crashed into Earth some 65 million years ago. (Art by Don Davis - COURTESY OF JOURNAL NATURE)
Phew.

After several weeks of irrational fears that a NASA satellite was plunging straight toward our front yards before it eventually landed in the Pacific Ocean, NASA has released some further encouraging news: The space agency has found more than 90 percent of the biggest asteroids that might pose a threat to Earth.

NASA’s sky-mapping spacecraft WISE was behind the discovery, noting that 911 of 981 of the largest asterorids — asteroids 3,300 feet wide or larger — have been found.

Scientists also say they now think there are fewer medium-sized asteroids than originally believed. New estimates say there are 19,500 asteroids out there that are between 330 feet and 3,300 feet wide.

WISE, which stands for Wide-field Infrared Survey Explorer, was launched in 2009 to map the entire sky of asteroids, comets, and other celestial objects.

By  |  03:57 PM ET, 09/29/2011

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