Dodging a Bullet In the "Stargate: SG1" TV series, a bad guy
known as Apophis kept taking shots at Earth and its heroes, but
he always missed. Fortunately for us, an asteroid named Apophis
won't have any more luck -- at least for quite a while. Apophis
was discovered six years ago as part of a search for asteroids
that might one day threaten Earth. It's more than twice the
length of a football field -- big enough to cause significant
damage if it hit us. And early calculations showed that it might
do just that in 2029. Because of the threat, the astronomers who
discovered the asteroid named it after the character from SG1.
As they tracked the asteroid and learned more about its orbit,
though, scientists determined that Apophis will miss us by about
20,000 miles. That scary close encounter raised a new concern:
that Earth might fling Apophis into just the right orbit to set
up a collision in 2036. Last year, though, new data and a more
precise plot of its orbit reduced the odds of a collision to
about one in a