Jupiter and Saturn are going to align in a way that has not been done since the Middle Ages, astronomers say. When the sun sets on December 21st, the day of the winter solstice, people are going to see a conjunction of Jupiter and Saturn which are going to come very close and look like a double planet. The last time this happened was 800 years ago.
"Alignments between these two planets are rather rare, they happen once every 20 years or so, but this coupling is extremely rarely because of how close the two planets will be, "said Rice University astronomer Patrick Hartigan.

"To be precise, a closer alignment of these planets took place on March 4, 1226."
Η approach of the two planets has started since summer. "On the afternoon of the nearest approach on December 21, they will look like a double planet, separated only by 1/5 of its diameter. full moonSaid Professor Hartigan.
The two planets are expected to be visible throughout Earth, as long as the weather allows everyone to enjoy the spectacle. But the best view will come about an hour after sunset - when the πλανήτες they will appear low in the western sky - and will look better near equator.
For those who miss this wonderful spectacle, the next opportunity will come in 2080. After that there will be no more opportunity until 2400.