This year has been a year unlike any other in recent memory and it will conclude with the return of a celestial event not seen for almost 800 years.
The two largest planets in the solar system, Jupiter and Saturn, will do something later this month not seen since the Middle Ages: forming what looks like a double planet. This celestial event has been dubbed the “Christmas star.” The rare occurrence will happen after sunset on Dec. 21, 2020, the start of the winter solstice.
“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 one another,” said Rice University astronomer Patrick Hartigan in a statement. “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.”
Between Dec. 16 and Dec. 25, the two planets will be separated by less than a full moon, Hartigan added.
“On the evening of closest approach, on Dec. 21, they will look like a double planet, separated by only fifth the diameter of the full moon,” Hartigan explained. “For most telescope viewers, each planet and several of their largest moons will be visible in the same field of view that evening.”
