Let earth-grazing show begin: 2008 Perseid meteor shower

William Atkins
Wednesday, 06 August 2008 21:20

Science - Space

For your best experience, find a location on a very dark night, away from any human-made lights. Although first observed at 9 p.m. the frequency of seeing meteors streaking across the sky will pick up at about 11 p.m. local time.

At that time, the radiant (the origin from which the meteors appear to come out of in the night sky) will be higher in the sky.

As the night progresses, the rate of meteors seen will increase each hour. The end of observations will be about 1.5 to 2 hours before sunrise.

The meteors and dust from Perseids originate from the Comet Swift-Tuttle, which is currently far beyond the orbit of the planet Uranus.

However, its tail of debris is as long as the distance between Uranus and the Earth, which is over 1.6 billion miles (2.6 billion kilometers).

Much of the collection of debris within Perseids is only a few thousands of years old. The debris collection is called the Perseid cloud, which all are formed when the heat of the Sun forces materials out from the icy comet.

Comet Swift Tuttle, the source (parent body) of the Perseid meteor shower, was discovered independently on July 16, 1862, by Lewis Swift and on July 19, 1862, by Horace Tuttle. Formally called 109P/Swift-Tuttle, it was lost for awhile, but rediscovered in 1992 by Japanese astronomer Tsuruhiko Kinchi.

Additional background on the Perseids is found at the Space.com website "Science and history of the Perseid meteor shower."