On Dec. 21, there will be a celestial event not seen in nearly 800 years according to KTLA-TV.

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Jupiter and Saturn will line up to create what is commonly known as the “Christmas Star” or “Star of Bethlehem.”

These two planets haven’t appeared this (relatively) close together since the Middle Ages.

“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,” Patrick Hartigan, astronomer at Rice University, told Forbes. “You’d have to go all the way back to just before dawn on March 4, 1226, to see a closer alignment between these objects visible in the night sky.”

Those planning to view in the northern hemisphere should point their telescopes to the southwest about 45 minutes after sunset to see the planets align on Dec. 21. However,  sightings can be seen throughout that entire week.

The pairing of two objects lined up in the sky is called conjunction by astronomers, and both planets have been drawing closer in appearance since October.

Jupiter will be the brighter planet with Saturn appearing dimmer to the right.

Both of the solar system’s giant planets will be gone from the night sky by Christmas.

The Bible mentions the Star of Bethlehem only a few times without enough details to determine what actually was in the sky.

Some astronomers say the Magi in the Nativity story may have witnessed a comet, supernova or the triple conjunction between Jupiter, Saturn and Venus.

According to Forbes, a star-sighting of this magnitude won’t occur again until 2080.

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