Jupiter and Saturn will appear as one for the first time in 800 years.
The two planets pass one another about every 20 years, according to the Mount Wilson Observatory. The planets will be separated by 0.1 degrees on the longest night of the year, December 21.
The timing of the event has led some astronomers to associate the “great conjunction” with the star of Bethlehem.
If you want to see the great conjunction, you should go outside an hour after the sunset and look southwest. Binoculars or a telescope will make it easier to see the two planets.