You might keep your eyes open for an occasional "shooting star" tonight, because Earth is scheduled to punch through a cloud of comet dust -- tiny grains of debris that vaporize as glowing streaks of light when they hit the upper atmosphere.
Tonight's meteor shower is little known and little studied. It's called the Ursid shower, because the meteors have their radiant in Ursa Minor, the little bear -- the constellation that contains the Little Dipper. If you trace the path of every meteor in the shower, they all appear to "rain" into the sky from the radiant. But you don't need to know where the Little Dipper is to follow the shower, because the meteors can appear in any direction.
The Ursids are one of the weaker meteor showers, though. In a typical year, they produce just a few meteors an hour. On rare occasions, though, the Ursids have managed to impress. Observers in eastern Europe saw an Ursid meteor outburst in 1945, and a similar outburst occurred in 1986.
This year will probably be quiet. People who live in the northern United States and Canada will likely have the best view, because the Little Dipper is in the far northern sky -- it's the home of the North Star -- and the higher the radiant is in the sky, the better. To see the most meteors, find a location that's away from city lights. Unfortunately, though, the Moon rises in the wee hours of the morning, so its light will overpower most of the Ursid meteors.
Script by Ken Croswell, Copyright 2008
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