Wednesday, November 13, 2019
Persaid History :: essays research papers
 Perseid History  This is the most famous of all meteor showers. It never fails to provide   an impressive display and, due to its summertime appearance, it tends to   provide the majority of meteors seen by non-astronomy enthusiasts.  The earliest record of its activity appears in the Chinese annals, where   it is said that in 36 AD "more than 100 meteors flew thither in the   morning." Numerous references appear in Chinese, Japanese and Korean   records throughout the 8th, 9th, 10th and 11th centuries, but only   sporadic references are found between the 12th and 19th centuries,   inclusive. Nevertheless, August has long had a reputation for an abundance   of meteors. The Perseids have been referred to as the "tears of St.   Lawrence", since meteors seemed to be in abundance during the festival of   that saint on August 10th, but credit for the discovery of the shower's   annual appearance is given to Quà ©telet (Brussels), who, in 1835, reported   that there was a shower occurring in August that emanated from the   constellation Perseus.  The first observer to provide an hourly count for this shower was Eduard   Heis (Mà ¼nster), who found a maximum rate of 160 meteors per hour in 1839.   Observations by Heis and other observers around the world continued almost   annually thereafter, with maximum rates typically falling between 37 and   88 per hour through 1858. Interestingly, the rates jumped to between 78   and 102 in 1861, according to estimates by four different observers, and,   in 1863, three observers reported rates of 109 to 215 per hour. Although   rates were still somewhat high in 1864, generally "normal" rates persisted   throughout the remainder of the 19th-century.  Computations of the orbit of the Perseids between 1864 and 1866 by   Giovanni Virginio Schiaparelli (1835-1910) revealed a very strong   resemblance to periodic comet Swift-Tuttle (1862 III). This was the first   time a meteor shower had been positively identified with a comet and it   seems safe to speculate that the high Perseid rates of 1861-1863 were   directly due to the appearance of Swift-Tuttle, which has a period of   about 120 years. Multiple returns of the comet would be responsible for   the distribution of the meteors throughout the orbit, but meteors should   be denser in the region closest to the comet, so that meteor activity   should increase when the comet is near perihelion (as has been   demonstrated by the June Boà ¶tids, Draconids and Leonids).  As the 20th-century began, the maximum annual hourly rates of the Perseids     					    
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