If you didn't see it elsewhere, here is an argument from an astronomer that the Star of Bethlehem may have been Jupiter. It's fascinating to me that we have computer programs that can reproduce the sky as it would have been on a night two thousand years ago. In principle, there's no reason you shouldn't be able to calculate the positions of various stars and planets a long time ago, assuming we correctly understand their motions today and nothing occurred that would significantly disturb the regularity of those movements. It would take a pretty major event to change the position of Jupiter, certainly.
What I like about the argument is the idea that no one but the highest-placed stargazers of the the day would have recognized it as significant. It is true that Babylonian civilization had astrologers who were even more accurate than the ancient Greeks, for reasons Tex will appreciate: because the Greeks took their data and tried to make models to explain them, which led to occasional inaccuracies in future predictions, while the Babylonians skipped models and simply figured from empirical data. The idea that this famous star may have been one seen as significant only to those steeped in the arcane traditions of the East is rather plausible.
In any event, it's a charming story for the holiday.