This month the full moon falls on Three Kings' Day, traditionally a day that celebrates the adoration of the magi, so we investigate the famous Star of Bethlehem story. Through the centuries there have been dozens of astronomical and astrological theories put forward as to what the Star of Bethlehem was. We look at a few of the more prominent theories and their shortcomings, finishing with what is plausibly the leading candidate, the astrological theory of Michael Molnar, though as we'll see, this explanation, too, is not without its problems.