A great conjunction is a conjunction of the planets Jupiter and Saturn. Great conjunctions occur regularly (every 19.6 years, on average) due to the combined effect of Jupiter's about 11.86-year orbital period and Saturn's 29.5-year orbital period. The last great conjunction happened on 21 December 2020. It was the closest great conjunction since 1623.
References[change | change source]
- Jupiter-Saturn Conjunction Series from 0 to 3000 AD. 
Other websites[change | change source]
- The Great Conjunction Archived 2014-01-18 at the Wayback Machine at GeoGebra
- Orbital Motion Simulation of Jupiter and Saturn at GeoGebra