On December 21, you can witness a rare event in the night sky that has not been seen in almost eight centuries.
The two largest planets in our solar system, Jupiter and Saturn, will align on Monday, Dec. 21 to create what’s sometimes referred to as the “Christmas Star” or the “Star of Bethlehem.”
When the planets line up on the day marking the start of the winter solstice, they will appear to form a double planet. It’s a rare event and one that hasn’t been seen since the Middle Ages, according to Forbes.com. But in reality, the planets won’t be close at all. It will just look like that to viewers on Earth.