Comet Swift–Tuttle
Discovery | |
---|---|
Discovered by | Lewis Swift Horace Parnell Tuttle |
Discovery date | July 16, 1862 |
Designations | |
1737 N1; 1737 II; 1862 O1; 1862 III; 1992 S2; 1992 XXVIII | |
Orbital characteristics | |
Epoch | October 10, 1995 (JD 2450000.5) |
Aphelion | 51.225 AU |
Perihelion | 0.9595 AU |
Semi-major axis | 26.092 AU |
Eccentricity | 0.9632 |
Orbital period | 133.28 a |
Inclination | 113.45° |
Last perihelion | December 11, 1992 |
Next perihelion | July 12, 2126 |
Comet Swift-Tuttle (formally designated as 109P/Swift-Tuttle) was independently discovered by Lewis Swift on July 16, 1862 and by Horace Parnell Tuttle on July 19, 1862.
The comet made a return appearance in 1992, when it was rediscovered by Japanese astronomer Tsuruhiko Kiuchi.
It is the parent body of the Perseid meteor shower, perhaps the best known shower and also among the most reliable in performance.
The comet is on an orbit which will almost certainly eventually hit either the Earth or the Moon, though not within this millennium.[1] Upon its 1992 rediscovery, the comet's date of perihelion passage was off from the then-current prediction by 17 days. It was then noticed that, if its next perihelion passage (August 14, 2126) was also off by another 15 days, the comet would very likely strike the Earth or Moon. Since the solid nucleus of Swift-Tuttle is about the same size as the object thought to have caused the Cretaceous–Tertiary extinction event, this was of some concern. This prompted amateur astronomer and writer Gary W. Kronk to search for previous apparitions of this comet. He found the comet was most likely observed by the Chinese in 69 BC and AD 188, which was quickly confirmed by Brian G. Marsden. This information led to a recalculation of its orbit, which indicated the comet's orbit was more stable than expected, making the threat disappear.[2]
Notes
- ^ Chandler, David L (2005-06-01). "Comet put on list of potential Earth impactors". New Scientist. Retrieved 2008-08-25.
- ^ Stephens, Sally (1993). "on Swift-Tuttle's possible collision". Astronomical Society of the Pacific. Retrieved 2008-08-25.
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External links
- 109P/Swift-Tuttle at NASA's Jet Propulsion Laboratory's Small-Body Database
- Periodic Comet Swift-Tuttle from NASA's Astronomy Picture of the Day