Earth Dodges Another Cosmic Bullet
(From the September/October 1999 issue of StarDate magazine)
New observations of asteroid 1999 AN10 show that it will miss Earth by about a quarter of a million miles -- the distance between Earth and the Moon -- when it swings past in 2027. It will also miss by safe distances in three other encounters later in the century. Earlier calculations had suggested the asteroid, which was discovered in January, could pass as close as 19,000 miles on August 7, 2027. But astronomers found "pre-discovery" images on 44-year-old photographic plates, allowing them to refine their calculations of the asteroid's orbit. Astronomers will look for new "Earth-crossing" asteroids, like 1999 AN10, with a rebuilt telescope at Palomar Observatory. The upgraded telescope should be able to find most of the large asteroids that could threaten Earth.
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