dipper@utastro.UUCP (Debbie Byrd) (08/04/84)
The comet that spawned the Perseid meteor shower is now late for its own return near the sun. More on Comet Swift-Tuttle -- in just a minute. July 28 Comet Swift-Tuttle This year the moon will be waxing to full just as the famous Perseid meteor shower reaches its peak on the mornings of August 11 and 12. That's too bad -- since the Perseids are generally one of the finest meteor showers of the year. But Perseid fans this year have something else to think about. Meteors that come in annual showers are actually debris from the bodies of comets -- and the comet that spawned the Perseid shower has been expected to return for several years now. This comet's name is Swift-Tuttle, whose first and only known return near the sun was in 1862. Swift-Tuttle is thought to have about a 120-year orbital period. That's not unusual for a comet -- in fact, it's similar to Comet Halley, which completes a single orbit once every 76 years. But Comet Halley has been seen at many returns during the past thousand years or so. Swift-Tuttle has been seen only once, in 1862. Swift-Tuttle was expected to return to our region of the solar system sometime between 1982 and this year -- but there's been no sign of it yet. That's important to meteor-watchers because when a parent comet returns, the offspring meteor shower can become incredibly spectacular. The 1980 Perseid shower was very rich -- 1981 wasn't as good -- and last year was downright disappointing to some long-time observers of the Perseids. Again, there will be a bright moon during the peak of the meteor shower this year -- and meanwhile those who expect the return of Comet Swift-Tuttle -- the comet that spawned the Perseid meteors -- are still waiting. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin