It is Christmas Eve as I write but, in 2020, a Christmas Eve like none that most of us will ever have seen: one with COVID, lockdowns, instructions to avoid meeting family and friends and unaccustomed solitude for many. It is also a Christmas Eve that follows a very special event: the so-called Great Conjunction of Jupiter and Saturn on December 21st, with its obvious connection to the time just before the Nativity when there was a Jupiter-Saturn conjunction, in 6BC.

I happened to be fortunate that, instead of being in foggy Madrid, I was in a (mostly) clear Tenerife for the critical day. As I set up shop on the seafront it was possible to contemplate the pairing – well-resolved, despite their proximity – between palm trees, along the busy pedestrian avenue. What was even more striking was that not one person of the hundreds that I watched, stopped and looked up at it. Not one. For the average member of the public, despite all the publicity, the two planets might as well have been invisible. To an astronomer like me, it was beautiful; to the average member of the public, it was totally unremarkable.

It was not that I missed the moment of closest approach: it was 18:21UT, while the photo that heads this posting was taken at 19:08UT, just three-quarters of an hour later, with the planets still at minimum distance.

This event started a three-day debate over WhatsApp among Herschel mission veterans, about the conjunction, the Star of Bethlehem, the veracity of Gospel accounts and of Biblical chronology. It also led to a deep examination of my own views from a group of hardened sceptics, who are used to unpicking highly technical documentation.

So, one thing that we could agree on was that an event like the 6BC Jupiter-Saturn conjunction would, on its own, be insufficient. As my social experiment on the seafront showed, there was nothing striking about the 6BC conjunction on its own. We agreed that, whatever the Star was, it had to be something that had special significance for the Magi.

Here, we run into the first problem. Even assuming that the Star did exist (and many biblical historians dispute that), there is no real agreement as to who the Magi were, or where they came from, so it is hard to understand their motives. Even more so when we remember that the Jews were forbidden to practice astrology (there was no “Jewish astrology”) and the arts of the Magi were either strongly discouraged, or even outlawed (according to the period) in Rome, so we have little idea of what events might have been particularly significant to the Magi.

Remember, the Magi were not Kings. King Herod did not treat them as kings, or as royal ambassadors. Even in times of war, royal ambassadors do not normally have to flee for their lives. The Magi only became kings in the 6th Century AD, by edict of the church. As the church reached a consensus that Jesus was the Son of God, to give him a higher status it was decided that as the figure of the Βασιλευς Βασιλεόν, the Basileus Basileon or “King of Kings”, he could not have been visited by anyone other than kings.

The word “Magi” is the biggest clue to their identity. Matthew states: ἰδοὺ μάγοι ἀπὸ ἀνατολῶν;  “Behold, there came wise men from the east”, as it is translated in the King James Version of the Bible. Here, the use of the word east (ἀνατολῶν – plural) refers to geography e.g. from a country in the east. The word μάγοι (magoi), the plural of µαγυς (magus), is usually translated as “astrologers” or “magicians” these days, indeed, it is the root of the word “magic” but, as Greek astronomer, Eleni Kalfountzou, points out, it used to have more meanings (e.g. the priest of a tribe). In Roman times the Magi were a caste of priests from Medea, in Northern Persia.

In 66AD, to seal Roman control over Armenia, the small country between Medea and the Caspian Sea, Nero gave the throne of the country to King Tiridates, but obliged him to travel to Rome to accept it. Tiridates travelled with an entourage of three thousand who, by all accounts passed along their route like a plague of locusts, obliging the countries and provinces that they crossed to feed and support them. Pliny the Elder, Tacitus and Dion Cassius all describe the visit in their histories, with Pliny being particularly cutting in his references, accusing Nero of “carrying out all kinds of stupidity”, but making the following interesting comment in Historia Naturalis, 30:6, 16-18:

“Magus ad eum Tiridates venerat Armeniacum de se triumphum adferens et ideo provinciis gravis… quaereat aliquis, quae sint mentiti veteres Magi“

The Magus Tiridates come to his court… and, with him, brought other Magi.

This is a particularly interesting reference. This is the sense of the word “Magi” that Matthew, living in Rome, would have been familiar with and would have intended. All four Gospels were, almost certainly written after the visit of King Tiridates.

One item of confusion to biblical scholars are the huge discrepancies between the Nativity accounts of Matthew and Luke. Luke talks of a census, of Caesar Augustus, of the inn and of shepherds. Matthew talks of the Star, the Magi and King Herod. Not only is there is only one item in common between the two – the baby Jesus – but Luke’s chronology is confusing, talking about a census, which is generally believed to be the 8BC census decreed by Augustus, but referring to Quirinius as Governor of Syria, which he was not until 7AD. While the 8BC census is in agreement with the commonly agreed date of the death of Herod in March/April 4BC, it was a Roman citizens only census and Joseph was not a Roman citizen as Judea was a Roman Protectorate. Here, we may never learn the truth. Did Quirinius have two postings to Syria? Did Luke confuse the 8BC census and a local registration? Was Augustus’ census combined with local registrations? Was the original meaning of Luke mistranscribed, or mistranslated later when the Gospels were compiled (e.g. one suggestion is that he intended to say “a census like that of Augustus”). Probably we will never know.

We know that Quirinius did organise a census in the region, because the above tablet attests it, but no date is given and that is often taken to suggest that Quirinus had an earlier posting in Syria, around the time of the 8BC census.

What of this conjunction? Between 1000BC and 4000AD there are no fewer than 309 conjunctions of Jupiter and Saturn. A Jupiter-Saturn conjunction takes place, on average, every 19.46 years. Most of these are ordinary conjunctions but, over 5000 years there are 28 triple conjunctions, in which there are three consecutive conjunctions over a six-month period, with the planets thrice closing and separating again before their definitive separation for another nineteen years.

You may have read that the 2020 conjunction was a “once in a millennium” event. Well, that is not quite true. The 1623 conjunction, was even closer and the one in 1563 was almost as good, although both occurred close to the Sun in the sky. Other conjunctions as good as or better than that of 2020 will occur in 2080, 2417 and 2477.

The median distance of approach by Jupiter and Saturn over five millennia is 39 arcminutes – a little more than the diameter of the Full Moon – while the largest possible separation is exactly double this (78 arcminutes), which occurred in 1306 and will again in 2795.

The famous 7BC triple conjunction was not one of the better ones, with separations of 59, 58 and 63 arcminutes between the two planets – twice the diameter of the Moon. The triple conjunction of 146/145BC was far more spectacular (separations of 11, 15 and 10 arcminutes) while, in 86 and 26BC, there were far closer single conjunctions. If people barely noticed the 2020 conjunction, why would the 7BC event be so important? The answer is that, without knowing the particular motives of the Magi, it is impossible to say. If the 7BC Triple Conjunction was the Star of the Magi, it must have had some special, astrological significance to them: but what?

We have said that there is great confusion between the Nativity accounts of Matthew and Luke. There is a third Gospel that writes of the Nativity and that is the Protoevangelium of James. Critics discount James, an Apocryphal Gospel, in other words, one that was not incorporated into the New Testament by the Council of Nicea, by saying that it is a much later work than the other Gospels. In fact, modern dating is that it was probably written about the same time as John, long before the New Testament was compiled finally in the 4th Century. In reality, bearing in mind the time scales involved and the fact that none of the three authors could have witnessed the Nativity, James is as contemporary with the events it describes as Matthew and Luke.

The biggest issue with James, one suspects, is that it counted with the disadvantage of being condemned by Pope Innocent in 405AD for its portrayal of Jesus as not having a normal, human birth. In other words, it was censured for taking the more mystical account of Matthew to an extreme unacceptable to the early church. This is a prejudice that lives on today, albeit in revised form.

What though does James say? Some of his comments are very interesting:

Take Chapter 17, for instance:

(1) Then, there was an order from the Emperor Augustus to register how many people were in Bethlehem of Judea.

(2) And Joseph said, “I will register my sons. But this child? What will I do about him? How will I register him?

Then, in Chapter 18:

(1) And he found a cave and led her there and stationed his sons to watch her,

(2) while he went to a find a Hebrew midwife in the land of Bethlehem.

This is particularly interesting. Go to the church of the Nativity in Manger Square in Bethlehem and you find at the end of a nave two, small staircases that lead down below to a series of small chapels, one of which is the Grotto of the Nativity, with its small, silver star, marking the supposed position of the manger. Note that the word used by James is “cave” – and here, we can have security in the translation, because we have multiple texts of James, some from as early as the 3rd Century AD, in contrast to the mostly fragmentary copies of the Gospels that have survived from prior to the 8th Century.

Tradition states that the church was originally built on the orders of Emperor Constantine, replacing a temple to Apollo built on the site by Emperor Hadrian to obliterate it as a site for Christian homage. This tradition also states that the original site of the Grotto was a cave, rather than a inn’s stable. The area around Bethlehem is full of these limestone caves, still used today by shepherds to give shelter to themselves and their flocks at night, which would have provided ready-made shelter in an emergency for travellers such as Mary and Joseph. It is a story that has a strong ring of authenticity to it.

What more does James say? Well, he makes more fascinating comments. Superficially, Chapter 21 is very similar to Matthew’s Nativity story:

(1) Now, Joseph was about to depart to Judea when there a great commotion in Bethlehem of Judea.

(2) For astrologers had come, saying, “Where is the one who has been born king of the Jews? For we saw his star in the East and came to worship him.”

(3) And when Herod heard, he was shaken up and sent servants to the astrologers.

(4) And he also sent for the high priests and questioned them in his palace, saying to them, “What has been written about the messiah? Where will he be born?”

(5) They said to him, “In Bethlehem of Judea, for so it has been written.”

(6) And he let them go. And he questioned the astrologers, saying to them, “What sign did you see about the one who has been born king?”

(7) And the astrologers said, “We saw a star shining with incredible brilliance amidst the constellations and making them seem dim.

(8) And so we knew that the king had been born in Israel and we came to worship him.”

(9) And Herod said to them, “Go and search. If you find him, report to me so that I also may come and worship him.”

(10) And the wise men departed. Then, the star which they had seen in the east led them until they came to the cave and stood over the head of the child.

(11) And when the astrologers saw him with his mother Mary, they took gifts out of their bags: gold, frankincense, and myrrh.

(12) And having been warned by the angel not to go into Judea, they returned to their country by another road.

Verse 1 is especially informative. It states clearly that quite time has passed, Mary has recovered from the birth and they are ready to return to Nazareth with the baby Jesus when the Magi – here translated as “Astrologers” – arrive. How long has passed since the birth, described in Chapters 18-20? Weeks? Maybe even months?

Whatever the Star was, it was visible for a long time. Long enough for Mary to recover from the birth. Long enough for the Magi to arrive from Orient. Long enough for them to spot it in the south, going before them from Jerusalem to Bethlehem, possibly having been lost to sight as it faded due to the bright nights of a Full Moon. Certainly, the Star was no instantaneous event.

James allows himself to get carried away in his description of the Star, although this could just be the way that astrologers state that the sign in the sky was of huge significance to them (this is a concept that a Jew, with no astrological tradition, would find hard to understand and put in words, in the same way that Mark struggled to explain Aramaic concepts in his broken Greek). Zoroastrian Magi from Medea though, would have been very familiar with the prediction of the Virgin birth and the coming of the Messiah, as it was so similar to their own traditions.

What is interesting though is that James combines elements of both Luke and Matthew in a much extended account of the Nativity, although removing a major problem with Luke’s account by not mentioning Quirinius and by making his text more consistent with the traditional, 5BC Nativity date and, at the same time, consistent with the revised calendar of Dionisius and of the early church.

I have already stated that I find the Molnar theory of the unobservable Jupiter occultation unconvincing, for multiple reasons. It is a big stretch to think that the Magi could calculate orbits sufficiently well to know that an occultation, theoretically visible from Persia, would happen. Even today, with a telescope it would have been a tough observing challenge. And the Antioch coin that supposedly shows it represents an astrological scene that was extremely common in Roman coinage over three centuries, with 10% of catalogued coins showing some variant on this scene. The coins of Nero and of the 3rd Century AD, among others, feature it often: it was not a Christian or Jewish symbol.

Now, we could say that the long-lasting star seen by the Chinese and Koreans in March 5BC is, by elimination, the only realistic candidate or known events. Observed for two and a half months before the monsoon rains would have hidden it from sight, it is consistent with a bright, long-duration nova.

However, the true mystery of the Star of Bethlehem is another. Even if the 5BC nova was the Star, what did it mean to the Magi? Why did they find it especially significant? How was this different to other events that they would have seen over the years?

What was it about what they saw that so motivated the Magi to make this dangerous journey? What did they think when they saw it? That is the mystery and one that we may never resolve.