On December 21st, Jupiter and Saturn — which are actually separated by more than 400 million miles — are expected to appear closer to each other in the night sky than they have for centuries.
The Arthur C. Clarke Institute for Modern Technologies said this spectacle can be witnessed at around 05:30 PM on the 21st of December.
Seen at the right hour, whether by telescope or the naked eye, the gas giants will be separated by roughly a fifth of the diameter of the typical full moon.
At this proximity, the planets will appear to touch or even form one large, brilliant star in the sky.
Since Jupiter takes a little less than 12 years to circle the sun and Saturn takes more than 29, the planets appear to earthlings to meet roughly every 20 years, in what astronomers call a “great conjunction.”
The last great conjunction occurred in May 2000.
Jupiter and Saturn last approached this closely to each other in July 1623, but as with the conjunction in 2000, it was hard to spot.
Astronomers say there won’t be another great conjunction this close until 2080.
