Great conjunction

A great conjunction is a conjunction of the planets Jupiter and Saturn.
Orbital Motion Simulation of Jupiter and Saturn
 The most recent great conjunction took place on 31 May 2000; the next one will be in late December 2020. Great conjunctions take place regularly, every 18–20 years, as a result of the combined approximately 12-year orbital period of Jupiter around the Sun, and Saturn's approximately 30-year orbital period. The 2000 conjunction fell within mere weeks after both had passed conjunction with the Sun, hence it was very difficult to observe without visual aid because the two planets rose only 30–45 minutes before sunrise, depending upon the location of the observer.
A greatest conjunction is a conjunction of Jupiter and Saturn at or near their opposition to the Sun. In this scenario, Jupiter and Saturn will occupy the same position in right ascension on three separate occasions over a period of a few months. Such tripled occurrences are actually known as triple conjunctions.
==In the years 1800 to 2100==
 Great conjunctions in right ascension
Date 	Time 	Angular distance	Elongation 	Zodiac sign
21 July 1802 	03:22:00	42' South 	37.9° East 	Virgo
25 June 1821 	00:05:09	1°15' North 	67.5° West 	Aries
22 November 1821 	23:49:55	1°20' North 	140.2° East	Aries
23 December 1821 	09:28:49	1°22' North 	108.5° East	Aries
25 January 1842 	22:22:31	32' South 	26.8° West 	Capricorn
25 October 1861 	15:11:20	52' South 	43.1° West 	Virgo
22 April 1881 	11:58:20	1°18' North 	1.0° East 	Taurus
28 November 1901 	06:10:38	27' South 	38.6° East 	Capricorn
14 September 1921	16:22:08	1°02' South 	6.2° East 	Virgo
15 August 1940 	13:18:42	1°15' North 	97.5° West 	Taurus
11 October 1940 	23:17:26	1°17' North 	155.0° West	Taurus
20 February 1941 	19:14:02	1°21' North 	67.7° East 	Taurus
18 February 1961 	14:42:37	14' South 	34.6° West 	Capricorn
14 January 1981 	07:58:37	1°09' South 	103.9° West	Libra
19 February 1981 	07:12:10	1°09' South 	141.2° West	Libra
30 July 1981 	21:32:22	1°12' South 	57.9° East 	Libra
31 May 2000 	10:13:27	1°11' North 	16.9° West 	Taurus
21 December 2020 	13:22 	6' South 	30.3° East 	Aquarius
5 November 2040 	13:19:46	1°14' South 	24.8° West 	Libra
10 April 2060 	09:01:25	1°09' North 	39.8° East 	Gemini
15 March 2080 	08:29:24	6' North 	43.8° West 	Aquarius
24 September 2100	01:40:38	1°18' South 	25.1° East 	Libra
 Great conjunctions in ecliptic longitude
Date 	Time 	Angular distance	Elongation 	Zodiac sign
17 July 1802 	22:57:00	39' South 	40.6° East 	Virgo
19 June 1821 	16:56:57	1°10' North 	63.3° West 	Aries
26 January 1842 	06:16:53	32' South 	27.1° West 	Capricorn
21 October 1861 	12:27:02	48' South 	39.7° West 	Virgo
18 April 1881 	13:35:59	1°13' North 	3.1° East 	Taurus
28 November 1901 	16:37:33	26' South 	38.2° East 	Capricorn
10 September 1921	04:13:03	57' South 	9.7° East 	Virgo
8 August 1940 	01:13:20	1°11' North 	90.9° West 	Taurus
20 October 1940 	04:42:14	1°14' North 	164.0° West	Taurus
15 February 1941 	06:36:25	1°17' North 	72.9° East 	Taurus
19 February 1961 	00:07:18	14' South 	34.9° West 	Capricorn
31 December 1980 	21:17:24	1°03' South 	90.9° West 	Libra
4 March 1981 	19:14:36	1°03' South 	155.9° West	Libra
24 July 1981 	04:13:35	1°06' South 	63.8° East 	Libra
28 May 2000 	15:56:27	1°09' North 	14.9° West 	Taurus
21 December 2020 	18:37:31	6' South 	30.1° East 	Aquarius
31 October 2040 	12:02:47	1°08' South 	20.8° West 	Libra
7 April 2060 	22:36:24	1°07' North 	41.9° East 	Gemini
15 March 2080 	01:49:55	6' North 	43.5° West 	Capricorn
18 September 2100	22:50:40	1°13' South 	29.4° East 	Libra
== As omens ==
Great conjunctions have attracted considerable attention as celestial omens. There has been some speculation https://www.myjewishlearning.com/article/jewish-astrology/ ,https://islamsci.mcgill.ca/RASI/BEA/Maimonides_BEA.htm , for example, that the so-called "Star of Bethlehem" was a great conjunction that occurred c. 7 BCE.Michael R. Molnar: The Star of Bethlehem: The Legacy of the Magi, Rutgers University Press, 1999 During the late Middle Ages and the Renaissance, great conjunctions were a topic broached by most astronomers of the period up to the times of Tycho Brahe and Kepler, by scholastic thinkers as Roger BaconThe Opus Majus of Roger Bacon, ed. J. H. Bridges, Oxford:Clarendon Press, 1897, Vol. I, p. 263. or Pierre d'Ailly, De concordia astronomice veritatis et narrationis historice (1414) and they are mentioned in popular and literary writing by authors such as DanteWoody K., Dante and the Doctrine of the Great Conjunctions,Dante Studies, with the Annual Report of the Dante Society, No. 95 (1977), pp. 119–134 or Shakespeare.Aston M., The Fiery Trigon Conjunction: An Elizabethan Astrological Prediction, Isis, Vol. 61, No. 2 (Summer, 1970), pp. 158–187 This interest is traced back in Europe to the translations from Arabian sources, most notably Albumasar's book on conjunction.De magnis coniunctionibus was translated in the 12th century, a modern edition-translation by K. Yamamoto and Ch. Burnett, Leiden, 2000
As successive great conjunctions occur nearly 120° apart, their appearances form a triangular pattern. In a series every fourth conjunction returns after some 60 years in the vicinity of the first. These returns are observed to be shifted by some 7–8°, so no more than four of them occur in the same zodiacal sign. To each triangular pattern astrologers have ascribed one from the series of four elements and thus four triplicities or trigons are formed. Particular importance has been accorded to the occurrence of a great conjunction in a new trigon, which is bound to happen after some 200 years at most.Etz D., (2000), Conjunctions of Jupiter and Saturn, Journal of the Royal Astronomical Society of Canada, Vol. 94, p.174 Even greater importance was attributed to the beginning of a new cycle after all fours trigons had been visited, something which happens in about 800 years. Since each 'element' (trigon) consists of 3 signs it takes 800x3=2400 for the whole process to start anew (relation with the cycle of Precession).
Originally a trigon was thought to last 240 years, and the full cycle 960 years; but later more correct estimation were provided by the Alphonsine tables. Despite the inaccuracies and some disagreement about the beginning of the cycle the belief in the significance of such events generated a stream of publications which grew steadily up to the end of the 16th century. As the great conjunction of 1583 was the last in the watery trigon it was widely supposed to herald apocalyptic changes; a papal bull against divinations was issued in 1586 and as nothing really significant had happened by 1603 with the advent of a new trigon, the public interest rapidly died.
=== Great conjunctions and US president deaths ===
According to financial astrologer Daniel T. Ferrera, whenever a great conjunction occurs during an election or inauguration year, the president is likely to die in office. Careful analysis shows that, although it remained correct from 1840 to 1960, this rule started to "lose its power" after 1980. However, even though those presidents did not die in office, they were still associated with significant national events. See the table below for details:
Presidents who were elected around a great conjunction
Election Year	President 	Died in office?	Date of Death or Incident	Cause of Death / Detail of Incident
1840 	William Henry Harrison	Yes 	4 April 1841 	Pneumonia
1860 	Abraham Lincoln 	Yes 	15 April 1865 	Assassination
1880 	James A. Garfield 	Yes 	19 September 1881 	Assassination
1900 	William McKinley 	Yes 	14 September 1901 	Assassination
1920 	Warren G. Harding 	Yes 	2 August 1923 	Heart attack
1940 	Franklin D. Roosevelt 	Yes 	12 April 1945 	Cerebral haemorrhage
1960 	John F. Kennedy 	Yes 	22 November 1963 	Assassination
1980 	Ronald Reagan 	No 	30 March 1981 	Shot but survived.
2000 	George W. Bush 	No 	11 September 2001 	Terrorist Attack
==See also==
*Triple conjunction
==Notes==
==References==
==External links==
* The Great Conjunction at GeoGebra
== Sources ==
* 
* 
Category:Astrometry
Category:Astrological aspects
Category:Conjunctions (astronomy and astrology)