The Star of Bethlehem is one of the most powerful, and enigmatic symbols of Christianity. For centuries historians have debated the nature of this biblical light that heralded the birth of Jesus. Was it purely a divine sign, created miraculously to mark Jesus' birth? Or was it an astronomical event in its own right?

Astronomy teacher and lecturer and writer for Australasian Science Magazine David Reneke believes astronomers may have found the answer - or at least something that fits all the known facts. With modern astronomy software programs astronomers can reproduce the night sky exactly as it was, thousands of years ago. Wouldn't it be good if astronomers could go back and have a look at the night sky of Christ's time - to see if they could spot the Christmas star?

"Well, we have, and we found out something startling. It looks like the Christmas star really did exist," Mr Reneke said.

Armed with an approximate date for the birth of Jesus from Matthew's version of the Bible he said the Star of Bethlehem was not just a localised event and could be observed by sky-watchers elsewhere in the world, not just by the Three Wise Men.

Now, historical records and modern-day computer simulations indicate that there was a rare series of planetary groupings, also known as conjunctions, during the years 3 BC and 2 BC.

"Like the final pieces of a difficult jig-saw puzzle, our fabled biblical beacon is starting to reveal itself," he said.

On August 12, 3 BC, Jupiter and Venus appeared very close together just before sunrise, appearing as bright morning stars.

The crowning touch came 10 months later, on June 17, 2 BC, as Venus and Jupiter joined up again in the constellation Leo.

This time the two planets were so close that, without binoculars, they would have looked like one single brilliant white beacon of light.

Jupiter was known as the planet of kings and it all took place in the constellation of Leo, denoting royalty and power. This could easily have been interpreted as a sign that the Jewish Messiah had been, or was about to be, born.

The whole sequence of events could have been enough for at least three astrologers to see this as sign in the heavens.

This conjunction itself was unprecedented. It occurred during the evening and would have really lit up the night sky. Was this the fabled Christmas star? It seems so.

Astrologers would imply from all this that Jesus was in fact, a Gemini.

"Now, this doesn't mean that astrology works," Mr Reneke said.

"We haven't ruled out other possibilities for the Star of Bethlehem but it does make our search more rewarding to find a truly interesting astronomical event that happened during the most likely time for the Nativity."

Whatever the Star of Bethlehem was, it has had more impact on humankind than any star before or since. It is also possible that the mystery of the star will never be completely solved.

For many of us though, it is the mystery itself that drives us to find the solution.