An astrophysicist is claiming that the "Star of Bethlehem" was not a star but a rare alignment of planets.

In his book, Grant Matthews, astrophysicist from the University of Notre Dame, shared his explanations for the Star of Bethlehem.

"It couldn't have been something really bright, spectacular, because the courts of King Herod apparently had no idea this was going on when these guys showed up," he told National Post in an interview.

"It was some subtle alignment in the sky ... not a bright comet with a tail and so forth. Just as sun was coming up on the morning - I think it's April 17 of 6 B.C. - they would have seen Saturn, Jupiter, the moon ... coming up just before the sun, and all lined up," Matthews added.

The rare planetary alignments are one that may never happen again:

  1. The sun, moon, Jupiter and Saturn were aligned within the constellation Aries.
  2. Venus was aligned with the constellation Pisces.
  3. Mercury and Mars were positioned within the constellation Taurus.

In a press release, Matthews explained the Magi -- Zoroastrian priests of ancient Babylon and Mesopotamia -- might have seen this alignment and signified to them that there was a newborn ruler in Judea. The Magi believes that the presence of Jupiter and the moon means the birth of a ruler with a special destiny while Saturn and presence of Aries in the vernal equinox are symbols of the giving of life.

United Press International reported that Matthews came up with the explanation after surveying historical, astronomical and biblical records in an attempt to recreate the night sky as seen from the Middle East at the time of Jesus' birth.

"I feel a kindred connection to these ancient Magi who earnestly scanned the heavens for insight into the truth about the nature and evolution of the universe, just as we do today," Matthews said.