Comet 1P/Halley

Comet Halley is definitely the most famous of all comets. Although it has a rather long period of revolution (about 76 years), it has probably been observed since the year 468 B.C. (or -467) when the first record by Chinese observers was dated (there are also Greek records which are related to this Halley apparition, and more dubious records of possible apparitions in 1059-8 B.C. from China, and 2467 B.C.). It was observed and recorded at all of its last 30 apparitions (perihelia) from 241 B.C. to 1986 A.D.; its next return will occur in 2062.

While in more ancient times, the comet was merely observed for histographical, religious, astrological and perhaps even more esoteric reasons, all its apparitions since 1531 have contributed to scientific advance:

In 1531, Peter Apian observed that the comet's tail was always oriented into the direction away from the sun.
In 1607 it was observed by Johannes Kepler and Longomontanus. Kepler thought it was moving along a straight line through the solar system.
In 1682, the comet was observed by Edmond Halley. By comparing the orbital elements derived from his own observations with that of the comet apparations of 1531 and 1607, he concluded that these three were the same object, and in 1705, he predicted its return in late 1758 or early 1759.
In 1758 and 1759, astronomers (in particular the young Charles Messier) took considerable effort to find the comet's predicted return. The comet was eventually found by the German amateur astronomer Johann Georg Palitzsch on the night of December 26-27, 1758. The comet was eagerly traced by a number of astronomers up to June 1759.
In 1835, on its second predicted return, the comet was investigated e.g. by Friedrich Bessel, who concluded that non-gravitational "rocket" or "jet" effects might change the comet's orbit unpredictably.
In 1910, the first photos and spectra of comet Halley were obtained (e.g. on Lick and Mt. Wilson Observatories).
In 1986, (uncrewed) spacecraft investigated comet Halley for the first time. ESA's Giotto performed a particularly sophisticated close encounter and returned exciting images and data of Halley's nucleus and coma.

We can only speculate what will be done on the comet's next return in 2062.

Links:

Mt. Wilson Observatory Museum: Halley's Comet 1910
ESA's Giotto spaceprobe has visited comet Halley in 1986
ASP's material on Halley's comet: The Return of Halley's Comet, TNL 1, 1985; A Special Issue on Halley's Comet, TNL 3, Fall 1985; What Have We Learned About Halley's Comet?, TNL 6, 1986
Comet Halley and Charles Messier - Comet Halley's 1758-1759 apparition
Comet Halley Descriptions and Homepages:
- Comet Halley info from Bill Arnett's Nine Planets
- Gary Kronk's Comet 1P/Halley page
- Comet Halley info from Calvin Hamilton's Views of the Solar System

Comet Halley Images:

Lowell Observatory image of Comet P/Halley 1910, computer enhanced false-color for brightness levels done at KPNO.
1P/Halley Images (actually lightcurves), JPL
Anglo Australian Observatory / U.K. Schmidt Telescope images of Comet Halley:
- AAT 46: Halley's Comet on December 9, 1985 (AAT)
- UKS 19: Halley's Comet on 12 March, 1986 (UKS)
- AAT 117: Comet Halley on April 9-10, 1986 (AAT)
- UKS 34: Comet Halley on April 9-10, 1986 (UKS)
- Misc 20: Comet Halley hanging in the Milky Way in 1986 (by David Malin)
ESO images of Comet Halley:
- Comet Halley captured at mag 28.2, distance 4.2 billion km (28.06 AU) from Sun, March 6-8, 2003. ESO VLT image.
Comet Halley Images by Giotto (NEO Program, JPL)
Comet Halley Images at SEDS:

Amateur images of Comet Halley:

Miscellania related to Halley:

"I came in with Halley's Comet in 1835. It is coming again next year (1910), and I expect to go out with it. It will be the greatest disappointment of my life if I don't go out with Halley's Comet." - Mark Twain (1835-1910)
(see Mark Twain Quotes)

Hartmut Frommert [contact]