Great Conjunction
Great conjunction A great conjunction is a conjunction of the planets Jupiter and Saturn . Great conjunctions occur regularly, every 19.6 years, due to the combined effect of Jupiter's approximately 11.86-year orbital period and Saturn's 29.5-year orbital period. When studying the Great Conjunction of 1603, Johannes Kepler thought that the Star of Bethlehem might be the occurrence of a Great Conjunction. He calculated that a triple conjunction of Jupiter and Saturn occurred in 7BC . The most recent great conjunction occurred on 31 May 2000; the next one occurs December 21, 2020 (21:08 UT). At this time Jupiter is 0.1 degree south of Saturn. The 2020 conjunction is the closest since 1623. The 2000 conjunction fell within mere weeks after both planets had passed their conjunctions with the Sun; hence, the event was difficult to observe without visual aid because the pair rose only 30–45 minutes before sunrise, depending on the location of the observer. Conjunctions