The large, gaseous planets Jupiter and Saturn will come together in December for a rare planetary alignment not seen since medieval times, astronomers said.
“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,” Rice University astronomer Patrick Hartigan said 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.”
The great conjunction, when the planets will overlap appearing as one larger planet, is between Dec. 16 and Dec. 25. Sky gazers can view the alignment from just about anywhere on Earth. The planets will be closest on Dec. 21.
“For most telescope viewers, each planet and several of their largest moons will be visible in the same field of view that evening,” Hartigan said.
The next time Jupiter and Saturn will be this close is March 15, 2080 and again sometime after the year 2400.