“Christmas Star” Appears Dec. 21 As Jupiter And Saturn Align

The first day of winter will be a historical one as Jupiter and Saturn align creating what is known as the “Christmas Star.”

On the night of December 21st, the great conjunction will be visible for the first time in over 800 years. Tennessee Tech Physics Department Chair Stephen Robinson said the two planets will be separated by less than a degree.

“This is something that doesn’t happen very often,” Robinson said. “About once every 19 and a half years, Jupiter and Saturn kind of pass each other in the sky. The exciting thing this year is that they are going to pass very close to each other. That doesn’t normally happen that they get that close.”

Robinson said just after sunset, look to the southwest 20 degrees up in the sky to see the celestial bodies converge. The sparkling light can be seen by the naked eye, but if you have a simple pair of binoculars, the planets moons can also be seen.

“The last time they were this close, and they could be seen in the night sky, because sometimes this happens when it is daylight for instance, or they are so close to the sun it is very difficult to see them,” Robinson said. “Back in the 1200’s was the last time they were clearly visible in the evening sky.”

While the point of merging occurs December 21st, the two planets are visible now. Robinson said each night people can see the two inch closer.

“The really bright one is Jupiter and the dimmer one pretty close to it is Saturn,” Robinson said. “You can see them right now. It is not like they are suddenly going to get very close together. They are approaching each other right now. They are about one degree apart in the sky right now.”

Robinson said the conjunction happening on December 21st is mere coincidence. Scientists have traced the path of the planets to see if this event is related to the nativity story. Robinson said the closest found was 7 B.C. which is outside the time scale.

Saturn takes 30 years to orbit around the sun while it takes Jupiter 12 years. The next time this will occur at a short distance will be on March 15, 2080.