Jupiter, Saturn To Look Like 'Double Planet'

Dec 16, 2020

Saturn, top, and Jupiter, below, are seen after sunset from Shenandoah National Park, Sunday, Dec. 13, 2020, in Luray, Virginia. The two planets are drawing closer to each other in the sky as they head towards a “great conjunction” on December 21, where the two giant planets will appear a tenth of a degree apart.
Credit Bill Ingalls/NASA

This year's winter solstice will bring a rare sight to our night skies  just in time for the holidays. Jupiter and Saturn will begin aligning Wednesday providing an end-of-year celestial treat.

The two planets move into conjunction — that is, alignment — every 20 years. But this year they will be so close, the closest since the Middle Ages,  1226 to be exact. They'll look like a "double planet."

“I just had my eyes checked; I’m 20/20; and so I’m predicting that I may be able to still see them as two separate points of light on the 21st,” said Wayne Wooten, a retired astronomer from Pensacola State College.

“The solar system is basically flat; as we formed 4.5 billion years ago, the planets condensed out around the sun’s equator,” said Wooten. “And because Jupiter is closer to the sun and moves faster, it will overtake Saturn once every 20 years.”

You won't need a telescope, but you'll have to find a good viewing spot and be on time. Avoid tall buildings or mountains, and look toward the low southwestern horizon right after sunset.

“Jupiter will be passing just below Saturn, and so close to Saturn that, unless you have really sharp eyes, you’re probably not going to be able to split them for at least two to three days there around the 21st,” Wooten said. “You know, it really shows you planetary motion.”

Stargazers can get a better view with a telescope or even a pair of binoculars. But Wooten says you’ll need to “look quick.”

“Because they’re getting close to the sun, and in January both of them will be behind the sun,” said Wooten. “My best guesstimate is the best viewing will be between 30 minutes and an hour after sunset for the next several days.”

In case you’re wondering, the next convergence of Jupiter and Saturn is in 60 years.

“They won’t get this close again until 2080; and I’m not particularly planning on that one,” said Wooten, 81. “Let’s enjoy this one while we can. It would be a great highlight for an otherwise pretty abysmal year.”

Dr. Wayne Wooten, retired Pensacola State College astronomer.
Credit Dave Dunwoody, WUWF Public Media

One of the previous convergences took place around the time of the birth of Jesus Christ. In the Scriptures, it’s said that the three wise men followed a star in the east to the manger in Bethlehem. Wooten points to Johannes Kepler for that theory. Kepler also discovered the rules of planetary motion.

“He believed that the close grouping of Jupiter and Saturn in 7 and 6 B.C., which we believe is about the actual time that Christ was born, was what might have caused the Persian astrologers, the Magi, to go west to first Jerusalem and then from there to Bethlehem.”
While this likely would be of great significance to the astrologers – those who followed the “wandering stars” — a.k.a. planets — it did not register with the general population.

“This was not the bright Christmas star that’s depicted on all your Christmas cards; when they get to King Harods’ court, those people don’t know anything special is happening at all,” Wooten said. It was something that the Magi saw and understood, but obviously people in Harod’s court, including his astrologers, are not even aware of.”

Another idea for the “wandering star” that may have caused the Magis to travel could have been a comet, disappearing behind the sun and then reappearing over Bethlehem.

“This is what the great Italian artist Giotto depicted in his famous portrait of the Christ Child and Halley’s Comet, above the birthplace,” said Wooten. “But Halley’s was not the right place at the right time to do that. And we don’t have good records from the time.”

More information – and eventually numerous photos of the meeting of Jupiter and Saturn – can be found at the Escambia Amateur Astronomers' Association's Facebook page.