Editing Triple conjunction (section)

== Between two exterior planets ==

These are the most interesting triple conjunctions, because all three conjunctions can be seen very easily, because of the great elongation of the planets or stars involved.

Triple conjunctions between the bright exterior planets are very rare: the last triple conjunctions between Mars and Jupiter occurred in 1789–1790, in 1836–1837 and in 1979–1980. The next events of this kind will be again in 2123 and in 2169–2170.

The last triple conjunctions between Mars and Saturn took place in 1779, 1877 (only in [[right ascension]]) and in 1945–1946. The next triple conjunction between these planets will occur in 2148–2149, in 2185 and in 2187.

For both at triple conjunctions between Mars and Jupiter and for triple conjunctions between Mars and Saturn it is possible that two such events follow at an interval of only 2 years. This last happened for Mars and Jupiter in 927 and 929 and will be again in 2742 and 2744. It last happened for Mars and Saturn in 1742–1743 and 1744–1745 and will occur again in 2185 and 2187.

Conjunctions between Jupiter and Saturn—so-called [[great conjunction]]s, and are sometimes triple (seven times between AD 1200 and 2400). The three conjunctions occur several months apart, over a broad range of elongations from the sun.
The most historically important triple conjunction was that one between Jupiter and Saturn in 7 BCE-5 BCE, which has been proposed as the explanation for the [[star of Bethlehem]]. Triple conjunctions between Jupiter and Saturn last took place in 1682–1683, 1821 (only in [[right ascension]]), 1940–1941 and 1981. It will not occur again until 2238–2239.

There are more frequent triple conjunctions of Jupiter with Uranus or Neptune. They are unspectacular, but offer a good possibility for amateur astronomers to find these dim planets. The last triple conjunction between Jupiter and Uranus was in 2010–2011 and the next will be in 2037–2038. The last between Jupiter and Neptune was in 2009 and the next will be in 2047–2048.

At each opposition, because of the visible loop movement of the planets, there are triple conjunctions between the planet and some stars. Triple conjunctions between planets and bright stars close to the [[zodiac]] are not so frequent (approximately 2 events in 10 years).