This year, the bright planets Jupiter and Saturn will align perfectly on December 21st to create what is commonly called the Christmas Star or the “Star of Bethlehem.†The Star of Bethlehem, or Christmas Star, appears in the nativity story of the Gospel of Matthew where “wise men from the East” are inspired by the star to travel to Jerusalem.
According to NASA, Jupiter and Saturn align with one another every 20 years or so, but not nearly as close together as they will be in 2020.
Monday will be the closest Jupiter-Saturn pairing since July 1623, when the two planets appeared a little nearer. This conjunction was almost impossible to see, however, because of its closeness to the sun. Considerably closer and in plain view was the March 1226 conjunction of the two planets — when Genghis Khan was conquering Asia. Monday’s conjunction will be the closest pairing that is visible since way back then.
While the event itself takes place on December 21st , the planets will be close in the sky in the days leading up to it and afterwards. To see the conjunction, look south-west as soon as the sun sets and find the brightest thing you can see.
The next time they will get this close together in our sky won’t be for another 60 years, so this is going to be a once-in-a-lifetime event for many people.
For astronomers around the world, it is an exciting and rare occurrence and we could all use something positive to end the year.