During this year’s winter solstice on December 21st, two of our solar system’s largest planets will appear to collide for the first time since the Middle Ages. This event, featuring Jupiter and Saturn, will show the two planets at one super bright spot of light in our skies.
Although the event is called a “double planet,” the distance between the two planets will actually be about five times the distance between Earth and the Sun.
Patrick Hartigan, an astronomer at Rice University explained to Forbes that you would have to go back to just before dawn on March 4, 1226, to witness the last occurrence of this “double planet” event. “Alignments between these two planets are rather rare, occurring once every 20 years or so, but this conjunction is exceptionally rare because of how close the planets will appear to be to one another,” he said.