Normally, we see Jupiter and Saturn apart from each other but Both the planets when become closest to each other, that’s a very rare sight to be seen in the lifetime.
On December 21st, 2020 Jupiter and Saturn will align on each other forming the Greatest Conjunction of two bright planets means Jupiter and Saturn since last seen before 800 years ago in March 4, 1226 similar to that would be seen on December 21st, 2020. It is the Greatest Conjunction because from Earth both planets Jupiter and Saturn would appear on 0.1 Degree(6.1 arc minutes), but still after their conjunction they will be far from each other at distance of over 730 million kilometres.
Although, the last Great Conjunction of Jupiter and Saturn was on May 18, 2020, the apparent distance between Jupiter and Saturn in the sky was almost 1.34 Degrees(68.9 arc minutes). Also, 400 years ago on July 16, 1623, Jupiter and Saturn appeared to be close to each other, but that was not as much close as of seen on December 21st, 2020.
The sight of the Greatest conjunction of Jupiter and Saturn can be seen with a naked eye but still if someone wants to see it with a telescope then he/she will definitely see the 4 moons of Jupiter revolving around it.
Another astonishing and Greatest conjunction of Jupiter and Saturn in which the giant planets are separated by just 0.1 Degree(six arc minutes) will arrive on March 15, 2080.
Actually, this 2020’s conjunction of Jupiter and Saturn is special because it coincides with the December solstice, which is the shortest day of the year in the northern hemisphere and the longest in the southern.
The sight of conjunction of these two giant planets coming closer to each other would be really outstanding. From this we can imagine that how much beautiful is our Observable Universe, about which we are still unaware.
Hope you got lucky to see the sight of the Great Conjunction of Jupiter and Saturn.