by Ted Pedas The Cosmos March 28, 1993 Known as the Perseids, this celestial display peaks on the night of Aug 11-12, when an average of 60 shooting stars an hour are visible for observers from a dark, rural location. A bright moon, city lights, and pollution will overpower the show. Meteors are small particles of matter traveling through space, the debris left behind by disintegrating comets. These tiny bits of material produce flickering flames of light as they enter Earth's atmosphere and die fiery deaths. The Perseid meteor stream is orbiting through space in the same path as its parent comet, Swift-Tuttle, named for the two 19th-century American astronomers who discovered it. Each August Earth intersects this orbit and the particles then penetrate the atmosphere in large numbers. As reliable and spectacular as the Perseids are, however, they become even better when Swift-Tuttle reaches the point in its orbit that brings it closest to Earth. FIRST RECORD: The first reliably recorded observation of Comet Swift-Tuttle came in 1862, in the midst of the United States Civil War. Its return was heralded by spectacular showers of shooting stars observed by soldiers on both sides for several nights. Sky watchers reported that sparks of fire flashed 400 to 500 times an hour. Some were bright and colorful; others appeared as dramatic fireballs. It was thought that Comet Swift-Tuttle traveled in a highly elliptical orbit that lasted 120 years. Its return was eagerly awaited in 1982, but to no avail. In September 1992 the meteor-producing comet was finally sighted and its brief visit to our corner of the solar system means we may be due for a rare intense burst of meteors this August. DUE AGAIN:Earlier this year, as Comet Swift-Tuttle swept past the sun and cut across the orbit of Earth it should have left a thick concentration of dust and grit in its wake. It is expected that our planet will encounter this debris on the night of Aug 11-12 and kindle the Perseids into an unusually rich performance. Astronomical calculations indicate that Earth will pass through the Perseids at 3:20 a.m. Unfortunately, the Perseids will be poorly visible from North and South America. Southern Europe will be on the favored night-side of the Earth for most of the time that the meteors are due to reach their peak. Noted meteorologist and astronomer Joseph Rao has been following the Persieds from land, air and sea for three decades. He reports that the stage may now be set for what he calls "an unforgettable sky show for favorably suited sky watchers on the night of Aug. 11-12 there is a chance that a very intense storm of meteors may appear the hourly rate of meteors may number in the tens of thousands. The return of Comet Swift-Tuttle has generated worldwide interest in observing this year's Perseids. MEDITERRANEAN VIEW: Viewers on the decks of ships in the Mediterranean Sea should have the best observing conditions in the world. This writer is serving as project co-ordinator for two Mediterranean voyages to view the Perseids. Both programs will feature evening sky watches and on-board lectures to prepare passengers for the celestial show. On the evening of Aug 11, both ships the Stella Solaris and Stella Maris will seek out the best vantage points to watch the Perseids, far from the atmospheric light pollution and other land-based obstructions that may mar viewing. On Board: Distinguished experts and lecturers will accompany both cruises. The Stella Solaris will carry former astronaut Scott Carpenter, Warren native and NASA shuttle astronaut Dr. Ronald Parise, renowned astrophotographer George Keene, and Eugenides Planetarium (Athens, Greeece) Director Dionysios Simopoulos. Rao, who is senior meteorologist for Compu-Weather Inc. and the source of the astronomical and meteorological calculations for the Farmer's Almanac, will lecture on the Stella Maris, joined by Dr. Warren Young, professor of Astronomy at Youngstown State University. In addition to ringside seats for viewing the Perseids, the tours include visits to historical and mythological sites in Greece, the Aegean Sea, Turkey, Italy and the Mediterranean Rivieras.
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E-mail: Ted Pedas |