What did The Three Wise Men see in the sky? the GAT will tell you about it

The GAT, Gruppo Astronomico Tradatese, is concluding its annual activity on Monday 14 December 2020, at 9 p.m., with an evocative online commemoration (free access from the GAT website) of the possible astronomical phenomenon that accompanied the birth of Jesus.

The president of GAT Cesare Guaita is given indeed a lecture on the subject: The revisited Star of the Magi. The occasion for this evening is provided by a completely exceptional phenomenon that will occur on the night of 21 December 2020. It is on that day when the two giant planets Jupiter and Saturn, which have been with us throughout the summer, will get closer to each other until they are just 0.1 degrees apart, this is such a minimal distance that they will appear to overlap.

It will be possible to watch this phenomenon as soon as it is dark, by watching  the couple of planets ( it is clearer and better with a pair of binoculars) on the west low horizon a couple of hours before the pair sets, around 7 pm.  Jupiter and Saturn have not come so close for 400 years and it will take another 80 years for the phenomenon to occur again.

However, at this point, we can ask ourselves what does the very narrow conjunction of Jupiter and Saturn has to do with the Bethlehem “star” , mentioned by Matthew in his Gospel. For sure, Matthew when he spoke about the “star”, had to mean an important astrological phenomenon especially for the Magi who as professional astrologists, they knew very well the celestial things. So it could also be an astronomical phenomenon that was showy to ordinary people. However, this phenomenon had to be something coinciding with the real date of the birth of Jesus that, according to the more recent calculus, happened in the 7  B.C. For sure, the Bethlehem star was not a comet.

 

The tradition of placing a comet on the Magi’s shed does not correspond with the historical reality. This tradition was born at the beginning of 1300 when Giotto drew (around 1304-1035) a “star with a tail” on the shed of the Nativity scene in the Cappella degli Scrovegni (Padova).

 

Giotto, with his artist’s eyes, had seen a great apparition of Halley’s comet in the sky, in 1301, and so he was inspired to paint this “star” in his “Nativity of Jesus”. Truth is, Halley’s comet went back to Earth in 12 BC, so it absolutely CANNOT be identified as “the star of the Magi.”

 

It was probably Kepler who guessed the right explanation when he noticed that, in 7 BC, Jupiter and Saturn approached each other up to about one degree of angular separation (twice the apparent size of the full moon), not once but three times in a row in the constellation of Pisces, on May 29, September 29 and December 4 respectively. This was a very rare event, because triple conjunctions between Jupiter and Saturn occur every 120 years, but it takes about 800 years for the phenomenon to occur again in a constellation as important to the Jews as the constellation of Pisces.

 

This approaching of the two planets developed over such a long period of time, so that it accompanied the Magi throughout their journey, seems to be an excellent candidate for the celestial event depicted in the Gospel of Matthew. Not least because, in recent years, computer simulations have provided increasingly convincing confirmation of this event.

All the more reason to take a fresh look at the ‘modern’ repetition of this phenomenon on the night of 21 December 2020.

 

 

Translated by Vittoria Bonanomi, Elisa Cairone and Debora De Benedetto

Reviewed by Prof. Robert Clarke