Look Up for a Christmas Celestial Event!
by Allie Shoulders, Director of Adult Discipleship
There is a lot of excitement about a developing celestial event, which will be at its most impressive on December 21. Jupiter and Saturn will pass in the sky and from our vantage point, with the naked it eye, will look almost like one planet. In a difficult year, this is a wonderful reminder that God’s creation continues to amaze and there is also a fascinating link to the Christmas story.
As many of you know, my husband Bob is an amateur astronomer, so I asked him to explain what is happening and what to look for:
Great Conjunctions: A conjunction of planets occurs whenever one planet passes another in the sky as they all travel around the Sun at different rates. From antiquity, Jupiter - Saturn conjunctions have been considered special. I've heard them called "great conjunctions". This is because they are the least frequent of the conjunctions of the planets the ancients could see (Mercury, Venus, Mars, Jupiter, and Saturn). They occur roughly once every 20 years. This may have been the longest duration periodic event known to the ancients and was a significant milestone event in their timekeeping. The upcoming great conjunction on December 19th is unusual in that it is a very close one, with Jupiter and Saturn coming within a quarter of a degree of each other.
People familiar with Astronomy and with the Bible have long speculated on the nature of the star which the Magi followed to Bethlehem in Matthew chapter 2:
"After Jesus was born in Bethlehem in Judea, during the time of King Herod, Magi[a] from the east came to Jerusalem 2 and asked, “Where is the one who has been born king of the Jews? We saw his star when it rose and have come to worship him.” ... 9 After they had heard the king, they went on their way, and the star they had seen when it rose went ahead of them until it stopped over the place where the child was. 10 When they saw the star, they were overjoyed."
According to the website http://www.observadores-cometas.com/Star_of_Bethlehem/English/Possible.htm, Johannas Kepler calculated in 1603 that a conjunction of Jupiter and Saturn would have occurred in 7 BC ( there's also a good deal of discussion about the year Jesus was born, by the way), and proposed that this could be the sign the Magi followed in the heavens. While there are other phenomena proposed as potential Christmas stars, including an occultation of Jupiter by Venus in 2 BC, a comet, a nova, and others, the 7 BC "great" conjunction is my personal favorite for several reasons. First, it took place in the constellation Pisces (the fish), which the ancients associated (so I've been told) with Israel. Second, it was recorded in the Babylonian records. Finally, the 7 BC conjunction was a special type called a triple conjunction, which occurs when both planets go into apparent retrograde (backwards) motion as they pass each other in the sky. All the outer planets (Mars, Jupiter, Saturn Uranus, Neptune), go into retrograde motion each year when they are in opposition (on the opposite side of Earth from the Sun), due to the Earth's motion around the Sun. When this happens at the same time that two planets are in conjunction, the planets pass by each other not just once, but three times in a single year! They also stop twice briefly in their journey together across the sky as they change directions. This happened during the conjunction of 7 BC. Could this be what is meant by "until it stopped over the place where the child was?"
This week, we can "wonder as we wander under the sky", watching the planets grow closer night by night. Are we watching the same sign that guided the Magi to Christ over 2000 years ago? The planets are obvious in the West in the late twilight. They set fairly early, so don't wait too late to look