The two largest planets in our solar system came closer together than they have been since the Middle Ages, and it’s happening just in time for Christmas - hence the nickname of the “Christmas Star”. While it’s not an actual star, the two planets will certainly make a bright splash in the night sky.
On the night of December 21, the winter solstice, Jupiter and Saturn appeared so closely aligned in our sky that they looked like a double planet. This close approach is called a conjunction. The fact that this event is happening during the winter solstice is pure coincidence, according to NASA.