The
theory that the Christmas star was a conjunction of planets is very old. There
are two main theories, one pointing to 7 B.C. and another to 3 B.C. Both appear here, with the 3 B.C.
theory first. There is further
information about the 3 B.C. theory and an animation
on a separate page.
Other
theories discussed on separate pages, including the nova theory, the angel theory, and the comet theory.
From Great Events from Bible Times (Garden City: Doubleday & Company, 1987).
An hour and twenty minutes before sunrise on 12 August 3 BC, the planet Jupiter rose in conjunction with Venus, the 'morning star.' This planetary alignment would have created a blazing light in the sky. Jupiter, considered astrologically 'Father of the Gods,' when conjoined with Venus could well have been interpreted as heralding the birth of a king, since Venus is the goddess of fertility.
Also of
possible significance to the nativity story is the fact, noted by an American scholar,
E.L. Martin, that Jupiter was stationary in the heavens on 25 December 2 BC,
having reached its orbital point for retrogression (a change in its direction
of movement). It would also have been in the direction of Bethlehem from
Jerusalem. This, he thinks, was the date of the Epiphany [arrival of the Magi
in Bethlehem]." (p. 133)
See an ANIMATION of this conjunction at sunrise from Baghdad
on August 12, 3 B.C., along with further comment on this theory.
From The Bible as History (New York: William Morrow and Co., 1956).
The timetable of this planetary encounter [conjunction of Jupiter and Saturn] when it is presented in the prosaic dating system of modern astronomical calculations goes something like this: About the end of February in 7 B.C. the clustering began. Jupiter moved out of the constellation Aquarius toward Saturn in the constellation of Pisces. Since the sun at that time was also in the sign of Pisces, its light covered the constellation. It was not until April 12 that both planets rose in Pisces heliacally with a difference of 8 degrees of longitude. "Heliacal" is the word used by astronomers to indicate the first visible rising of a star at daybreak.
On May 29, visible for fully two hours in the morning sky, the first close encounter took place in the twenty-first degree of Pisces with a difference of o degrees of longitude and of 0·98 degrees of latitude.
The second conjunction took place on October 3 in the eighteenth degree of the constellation of Pisces.
On December 4, for the third and last time, a close encounter of the planets Jupiter and Saturn took place. This time it was in the sixteenth degree of Pisces. At the end of January in the year 6 B.C. the planet Jupiter moved out of Pisces into Aries.
"We have seen his star in the east" (Matt. 2:2), said the Wise Men, according to the Authorized Version. Ingenious textual critics discovered that the words "in the east" are in the original "En te anatolé·," the Greek singular, but that elsewhere "the east" is represented by "anatolai," the Greek plural. The singular form "anatolé" has, it is maintained, quite a special astronomical significance in that it implies the observation of the early rising of the star, the so-called Heliacal rising. The translators of the Authorized Version could not have known this.
If this exposition of the text is accepted, the translation, in the jargon of these astronomical experts, would read as follows: "We have seen his star appear in the first rays of dawn." That would have corresponded exactly with the astronomical facts.
But why this ancient learned expedition of the three Wise Men to Palestine when, as we know, they could see the occurrence just as well in Babylon? The sky-gazers of the East in their capacity as astrologers attached a special significance to each star. According to the Chaldeans, Pisces was the sign of the West, of the Mediterranean countries; in Jewish tradition it was the sign of Israel, the sign of the Messiah. The constellation of Pisces stood at the end of the sun's old course and at the beginning of its new one. What is more likely than that they saw in it the sign of the end of an old age and the start of a new one!
Jupiter was always thought of by all nations as a lucky star and a royal star. According to old Jewish tradition Saturn was supposed to protect Israel; Tacitus equates him with the god of the Jews. Babylonian astrology reckoned the ringed planet to be the special star of the neighboring lands of Syria and Palestine.
Since Nebuchadnezzar's time, many thousands of Jews had lived in Babylon. Many of them may have studied at the School of Astrology in Sippar. This wonderful encounter of Jupiter with Saturn, guardian of Israel, in the constellation of the "West country" of the Messiah, must have deeply moved the Jewish astrologers, for, according to astrological ways of thinking, it pointed to the appearance of a mighty king in the west country, the land of their fathers. To experience that in person, to see it with their own eyes, that was the reason for the journey of the wise astronomers from the East.
On May 29 in the year )7 B.C. the first encounter of the two planets was observed from the roof of the School of Astrology at Sippar. At that time of year the heat was already unbearable in Mesopotamia. Summer is no time for long- and difficult journeys. Besides that they knew about the second conjunction on October 3. They could predict this encounter in advance as accurately as future eclipses of the sun and moon. The fact that October 3 was the Jewish Day of Atonement may have been taken as an admonition, and at that point they may have started out on their journey.
Travel on the caravan routes even on camels, the swiftest means of transport, was a leisurely affair. If we think in terms of a journey lasting about six weeks, the Wise Men would arrive in Jerusalem toward the end of November. (pp. 349-351)
Astronomer Nick Strobel comments on this theory and other theories at his web page http://rampages.onramp.net/~binder/Xmastar.html Here's his comment on the conjunction theory:
There were two astronomical events involving conjunctions of planets around the time of Jesus' birth---the triple conjunction of Jupiter and Saturn in Pisces in 7 B.C.E. and the near-conjunction of Mars, Jupiter, and Saturn in Pisces in February 6 B.C.E. A conjunction is when two or more objects appear very close together on the sky. Pisces is associated with the Jewish people in astrology, so when Jupiter and Saturn passed very close to each other three times during the span of several months in 7 B.C.E. it was a notable event. Adding to the significance was that the triple conjunction in Pisces happens about once every 900 years. The first conjunction of the 7 B.C.E triple conjunction occurred in late May when the wise men may have started their journey. The second conjunction occurred in late September when they were visiting King Herod and the third conjunction appeared in the south towards Bethlehem in early December after Herod had sent them on their way. The close grouping of Mars, Jupiter, and Saturn to within 8 degrees of each other in Pisces occurs only once every 800 years. Jupiter was the ``star'' of royalty and luck and Saturn was the star of the Mesopotamian deity who protected Israel. Both of these rare conjunctions could have been predicted by the ``wise men from the East'' and could have been interpreted by them that a great king was to be born in Israel (Herod, king of the Jews at the time and very paranoid about being displaced, was therefore upset at this news). Though Jupiter and Saturn never got close enough together to be confused as a single object, the word ``star'' had a different meaning to the wise men than it does for us today and their definition could have included a planetary conjunction.