Apophis
To the people of ancient Egypt, the god Apophis was the embodiment of darkness and chaos; each night, he tried to devour the Sun god, Re, as he passed through the underworld. To the people of Stargate Command in the TV series SG-1, the false god Apophis was one of the leaders of an alien race intent on destroying Earth and enslaving humanity. And because of his nasty reputation in both history and fiction, a team of astronomers thought that Apophis was the perfect name for an asteroid that once appeared to be on a collision course with Earth.
Apophis was discovered two years ago as part of a search for asteroids that might one day threaten Earth. If Apophis were to hit Earth, it's big enough to wipe out a large city.
Early calculations showed that it might do just that in 2029. But as astronomers tracked the asteroid and learned more about its orbit, they ruled out that possibility. Instead, they found that Apophis will fly about 20,000 miles above Earth's surface.
That close approach raised a new concern: that Earth might fling Apophis into just the right orbit to set up a collision in 2036. But continued observations have allowed astronomers to all but rule out that possibility; the odds of a collision are only about one in 30,000.
Even so, NASA will continue to track Apophis closely. And scientists are looking at ways to deflect Apophis or other asteroids that really do threaten Earth. More about that tomorrow.
Script by Damond Benningfield, Copyright 2006
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