Jupiter, Saturn to look like double planet for first time since Middle Ages

Just after sunset on the evening of December 21, 2020, Jupiter and Saturn will appear closer together in Earth’s night sky than they have been since the Middle Ages, offering people the world over a celestial treat to ring in 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. “You’d have to go back to just before dawn on March 4, 1226, to see a closer alignment between these objects visible in the night sky.”

Though the best viewing conditions will be near the equator, the event will be observable anywhere on Earth, weather-permitting. Hartigan said the planetary duo would appear low in the western sky for about an hour after sunset each evening.