What was the Star of Bethlehem?

It may have been a comet seen in the spring of 5 BC

The Chinese reported another celestial visitor early in 5 BC - a"broom star" on the borders of the constellations Aquarius and Capricornus. Though some astronomers think this was a nova - an explosion on a dwarf star - Colin Humphreys, a scientist at Cambridge University, argues that it was a comet. And Humphreys is convinced that this tailed wonder was the Star of Bethlehem. The Chinese records show that the celestial visitor was visible for 70 days - long enough to guide the Magi to Bethlehem. In this case, Jesus was born in the spring of 5 BC.

But other scholars believe that a comet doesn't fit the bill. The Magi were not kings, but Babylonian astrologers. They didn't spend their time looking at the sky, and logging unexpected events such as comets. Like the astrologers of today, they were calculating the positions of the Sun, Moon and planets, and their relations to each other. This enabled them to "predict" events months or even years in advance.

Before people knew what the stars and planets actually were, they put their faith in the movements of heavenly bodies. The "wise men" who could predict those movements became incredibly powerful, because human destiny lay in their hands.

So, the Christmas Star may have been something much more subtle - so arcane that it may not have been evident to those without the astrological knowledge...

In recent years, various scientists have tried to reinterpret the evidence, while entering into the mindset of the astronomer-astrologers of 2000 years ago, to find out what heavenly apparitions would have been important for them. David Hughes, of Sheffield University, cites a "triple conjunction" between the giant planets Jupiter and Saturn that took place in 7 BC. In May, September and December of that year, the two planets drew close together in the sky.

It may have been a triply-repeated close approach of Saturn and Jupiter in 7 BC

Astrologically, the conjunctions were laden with meaning. Jupiter was the king of the gods, Saturn represented both Palestine and the principle of justice, while Pisces was the zodiacal sign of the Jewish people. The Magi - looking at their astrological charts - would have interpreted the conjunctions as a sign that a Jewish Messiah would soon be born. Hughes concludes that Jesus was born in the autumn of 7 BC.