The New Testament account of the appearance of the "star of Bethlehem" is one of the enduring symbols of the Christmas season. But its true nature has has also been the focus of controversy and debate. Was the star of Bethlehem a paranormal event - a miracle - proclaiming the birth of the Messiah? Was it a UFO? Or was it a natural, if spectacular, celestial event that happened to take place at the same time that some historians reckon that Jesus was born? Here's the Biblical account and the latest scientific theories (and some other unconventional theories) as to what the three Magi might have followed more than two thousand years ago.