Mike Molnar was a lot more interested in expanding his coin collection than figuring out the identity of the Star of Bethlehem when he ran across a 2,000-year-old coin at a coin show back in 1990.

But the image on the coin, of a ram looking over its shoulder at a star, sent the Rutgers University astronomer to dusty astrological texts to interpret its meaning. And what he found was the key, he believes, for unlocking the secret of the Star of Bethlehem.

The Star of Bethlehem has mystified and intrigued Bible scholars and astronomers (and those who fancied themselves a bit of both) for centuries.

The second chapter of Matthew's Gospel describes a unique celestial phenomenon that somehow escaped the notice of King Herod and the rest of Judea yet attracted mysterious visitors from the distant east, seeking a newborn king.

A number of celestial events have been proposed to explain the Bethlehem Star. A newly revised Bible Handbook, issued this year by the Zondervan Publishing House, states "there's one and only one astronomical object" that meets all of the Biblical criteria: a comet.

Molnar, who earned his Ph.D. from the University of Wisconsin in 1971, is sure it's not a comet. In an interview, Molnar said ancient astrology texts never refer to the birth of anybody related to a comet. Comets usually signal disaster, such as a war or the death of a king, he said.

In those ancient texts Molnar discovered that Aries the Ram was the zodiac symbol for the ancient kingdom of Judea, something that most scholars had apparently missed. Its appearance on his coin, minted in Antioch around A.D. 6, probably symbolized the solidification of Roman rule of the region.

Based on that information, he then went looking for the kind of celestial event ...