During Christmas week, there is a one-time super conjunction of the two largest planets in the solar system, Jupiter and Saturn.
This “poinsettia” or Christmas kiss, as it was also called, will be the next that the two gas giants have seen in the sky since 1623.
However, this conjunction was not visible in northern latitudes. You would have to go back to 1226 to get a comparable conjunction visible in the Irish sky.
This imminent conjunction will be the next passage of the two planets in this millennium by Christmas Day 2874.
To the naked eye, the two gas giants will look like a single star when they make their next pass on December 21st, the day of the winter solstice, when they appear only a fifth the diameter of the moon apart.
Fortunately, the heavenly festival of conjunction will also be available on the days on either side of closest rapprochement and will be deeper in heaven with each passing day.
Such a close encounter won’t happen again until March 15, 2080, but that won’t be as close as this one.
The conjunctions occur roughly every 20 years, when the orbits of Jupiter and Saturn are aligned according to our view of Earth.
The Irish Times’ heavenly diary writer John Flannery recommends looking for the closest rapprochement between 4:45 p.m. and 6:30 p.m. Monday evening.
He says, “When twilight fades on the evening of the winter solstice on December 21st, after 4:45 pm, first look deeply over the southwestern skyline with binoculars to see Jupiter with adjacent Saturn.
“At 5:30 p.m. the two are less than a fist’s breadth at arm’s length above the horizon and are sinking quickly, but they are in a darker sky and are easier to see with the naked eye.
“Half an hour later, that height will halve, and the two planets will likely appear lower if you don’t have a clear view to the southwest. Jupiter and Saturn then leave the evening sky stage at 6:30 p.m. and draw a final curtain for the drama. “
In the past, planetary conjunctions were seen as harbingers of momentous events. A conjunction of Jupiter and Saturn in 1583 was so feared that many felt that it was the end of time.
To curb growing public concern, the then Pope issued a bull in 1586 that banned all divination practices.
Our understanding of the nature of planets began after the Italian astronomer Galileo Galilei popularized the use of the telescope in the 1610s.
“Most people these days tend not to think so mystically and religiously because science cannot measure influence from the planets that can affect us on earth,” said astronomer Dr. Stuart Clark, the author of Beneath the Night: How the Stars Formed the History of Mankind.
“The big conjunctions are still nice to look at. There are perfect ways to watch the great forces of the universe moving these planets through their orbits. It was exciting to see Jupiter and Saturn move closer and closer together in the fall.
“Events like the great conjunction in particular inspire us to look at the beautiful night sky and think about the meaning of the whole.”