Jupiter and Saturn are about to align in a way that hasn't happened since the Middle Ages, astronomers say. When the sun sets on December 21, the day of the winter solstice, people are going to see a conjunction of Jupiter and Saturn, which will come so close together that it will look like a double planet. The last time something like this happened was 800 years ago.
"Alignments between these two planets are rather rare, occurring once every 20 years or so, but this conjunction is extremely rare because of how close the two planets will be," said Rice University astronomer Patrick Hartigan.
“In fact, a closer alignment of these planets occurred on March 4, 1226.”
The approach of the two planets has been underway since the summer. “On the afternoon of closest approach on December 21 they will look like a double planet, separated by only 1/5 of the diameter of the full moon,” said Professor Hartigan.
The two planets are expected to be visible from all over the Earth, as long as the weather allows everyone to enjoy the spectacle. But the best views will come about an hour after sunset – when the planets will appear low in the western sky – and will be best seen near the equator.
For those who miss this magnificent spectacle, the next opportunity will come in 2080. After that there will not be another chance until 2400.
