23/12/2011 17:32 GMT | Updated 22/02/2012 05:12 GMT

Witness the Star of Bethlehem for Yourself

"In the time of King Herod, after Jesus was born in Bethlehem of Judea, wise men from the East came to Jerusalem, asking, where is the child who has been born king of the Jews? For we observed his star at its rising, and have come to pay him homage." Gospel of St Matthew

What was the star? Only the Wise Men saw it 2000 years ago, but if you solve the clues then anyone with a computer and a simple starmap program can witness the Star of Bethlehem, just as it hung over the dusky midnight skies of the first noel.

The Star is mentioned only in the Gospel of St Matthew, even though the Gospel of St Luke also gives an account of the birth of Christ. Why no mention of the star in Luke? We don't know, but Mark, the earliest Gospel, provides much of the material for both Matthew and Luke, depicting Jesus as a man and the son of God. It is Matthew's Gospel that aims to proclaim Jesus as the fulfilment of ancient prophecy, so perhaps it is the place to mention the star?

Surprisingly for some, the Star is not only mentioned in the Bible. The non-biblical text called the Protoevangelium of St James has a description that is very different from Matthew; "And the wise men said; 'We saw how an indescribably greater star shone among these stars and dimmed them so that they no longer shone.'" The explanation for the difference may lie with the need for the writer of the Protoevangelium to associate the Messiah with a great star. For centuries self-proclaimed Messiahs, needed their own star for divine approval. In the second century AD, for example, the rabbi Aquiba proclaimed Simeon Bar Kosba as the Messiah. Kosba then changed his name to Simeon Bar Kokhba meaning "son of a star".

The Bible gives us an indication to the date. The reason why Joseph and Mary travelled from Nazareth to Bethlehem was the census decreed by Emperor Augustus around 8BC. The star and Jesus's birth must have occurred about that time.

It seems significant that the arrival of the Magi came as a great surprise to Herod and his advisors, suggesting they had not seen the star, which rules out a brilliant light as stated in the Protoevangelium. Yet the Magi saw it and undertook a journey of perhaps a thousand miles. Upon reaching Jerusalem they were told of the prophecy of Micah. "But thou, Bethlehem Ephratah, though thou be little among the thousand of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel."

Another important clue is that the Magi saw the star in the east. Some believe this to be an error in translation from "en te anatole", which is a phrase that has a special astronomical significance. It means that the star was up all night, rising at sunset and setting at sunrise, one of the five principal astrological positions of the Babylonians when a celestial body had its maximum influence on worldly events.

Herod sent the Magi to Bethlehem telling them to let him know where the Christ-child was so that he could also worship him. Herod knew of the prophesy that a king was promised to Israel, so the consequences for any claimant to the throne of David would be severe. When the Magi failed to return he used the old prophecy that the star would appear two years before the birth of the Messiah to justify the slaughter of the innocents, or perhaps about 30 male children in Bethlehem.

In Matthew's Gospel there is one of the major problems in the interpretation of the star. The Magi said it "went before them" and stood over the place where Jesus was born. This we cannot explain. All astronomical objects that last more than a few seconds are so far away that they cannot "stand over" any particular spot on Earth. Is this just poetic licence I wonder?

The Magi were overjoyed to see the star again on their way to Bethlehem. Is this another clue? Had they lost it, or did it appear twice? If they had then it rules out astronomical events that occur only once. Some researchers believe that the wise men saw the star for the first time in their homeland and having heard that the Messiah would be born in Bethlehem saw the star for the second time on their way there.

These then are the clues is there anything sources that satisfies them?

It could be a miracle to mark the birth of Christ, but many theologians believe that a miracle is unnecessary and that a natural event could be the explanation. It could be fictitious, a literary invention but if this were the case then why is the star of Matthew so mundane when compared with the brilliant star of the Protoevangelium? The tale of Matthew seems so ordinary, so matter of fact.

Many objects and events have been suggested as the Star of Bethlehem, ranging from exploding stars, meteors, Venus and even Halley's Comet. Venus, the second planet out from the Sun, can be the most brilliant object in the sky after the Sun and the Moon, but it can't be the "star" because ancient astrologers would have known all about it. Halley's Comet was spotted by the Chinese on 25 August in 12BC but as a contender for the Star of Bethlehem it is four years early. There were a couple of other comets in the more appropriate timeframe of 8-6BC but none of them really fits. Also, comets had little astrological significance at the time.

But there is another clue that comes from much later. In 1377 an unknown author wrote in the chronicles of Worcester Priory about a celestial event in AD1285. Jupiter and Saturn had come close together, and our scholar writes that it had not happened since the Incarnation. Centuries later, Johannes Kepler, last of the great astrologer-astronomers, also believed that a conjunction - the term meaning close approach of planets - of Jupiter and Saturn was the "Star" of Bethlehem. During Christmas 1603, from his observatory near Prague, he watched as Jupiter and Saturn came close together in the sky in the constellation of Pisces. He calculated that the last time it had happened was in AD799, and the time before that 7BC.

Using any starmap program you can go back to the year 7 and 8BC and see Jupiter and Saturn coming together three times. On 27 May in 7BC they paused at one degree apart, and two months later had separated to three degrees. They came together two more times, being only a degree apart on 6 October and on 1 December, before the graceful triple conjunction ended.

To the Magi the events unfolding in the sky were important. Saturn was identified with the God of Israel, and Jupiter with the Messiah. They had come together in the constellation of Pisces the water sign. Water falls to Earth and makes it fertile, believed to be the role of Israel among nations. This message was so powerful that it compelled them to travel.

We can stretch the reasoning a little further. If Jesus was born in 7BC, and if the conjunction theory is correct, it points to the birth of Jesus in August or September. We could take the so-called acronychal rising of Jupiter and Saturn when they were in the sky all night and at their point of greatest astrological significance. This occurred on the evening of Tuesday 15 September 7BC. Is this the exact birthdate of Jesus?