Come sunset Dec. 21 in any time zone around the world, Jupiter and Saturn seemingly will merge into a single bright point of light low in the western sky.
The Great Conjunction of 2020 will yield an expected spectacular astronomical sight involving the two planets unseen in nearly eight centuries. The conjunction will see bright white Jupiter and fainter yellowish Saturn separated by 0.1 degree, about one-fifth the diameter of a full moon. Binoculars will reveal the slim separation, but to the unaided eye, the planets will appear to converge.
The close alignment occurs as Jupiter laps Saturn as they orbit the sun.
The two planets have been approaching conjunction — a point when planets or other bodies as seen from Earth are near each other in the night sky — all year. The hulking orbs appear in conjunction about every 19.8 years, but not every close alignment is as near as this one. The last occurred May 28, 2000. The last time Saturn and Jupiter appeared this close was July 16, 1623.
That the conjunction is occurring near Christmas Day has given rise to talk about the Star of Bethlehem that the Gospel of Matthew describes in his telling of the birth of Jesus.
But the description of the star “is a very minor part of the infancy narrative,” said Jesuit Br. Guy Consolmagno, director of the Vatican Observatory. “It’s so unimportant that Luke doesn’t talk about it and yet it has captured our imagination.”
It’s what the star represents — the birth of Jesus — that is the real story, Consolmagno said.
Ideas about the Star of Bethlehem range from the natural — a great conjunction of Saturn and Jupiter near the time of Jesus’ birth or a comet — to the supernatural as a sign from God. Or it could have been a metaphor used by St. Matthew “to show how important Jesus’ birth was to humanity,” said amateur astronomer Fr. James Kurzynski.
“We need to remember that the Star of Bethlehem could have had different meanings for the people that Matthew was writing to,” Kurzynski explained.
He suggested Matthew may have even meant that Jesus’ birth was the “great light” bringing people out of the darkness in which they walked, as told in the Book of Isaiah.
Whatever the Star of Bethlehem, Kurzynski and Consolmagno said the upcoming astronomical event can allow people time to step outside to observe the beauty of creation and to realize that God is greater than any planetary dance, especially as the world continues to battle the coronavirus pandemic, confront political divisiveness and experience social ills.
The Jesuit astronomer encouraged people to take the time to look at the night sky any time.
“Spend some time away from people, but also away from your house. Spend some time with nature and remember that God is there.”