“What is most rare is a close conjunction that occurs in our nighttime sky, said Vanderbilt University’s David Weintraub, an astronomy professor. I think it’s fair to say that such an event typically may occur just once in any one person’s lifetime, and I think ‘once in my lifetime’ is a pretty good test of whether something merits being labeled as rare or special.”
It was the closest Jupiter-Saturn pairing since July 1623, when the two planets appeared a little nearer. That conjunction was almost impossible to see, however, because of its closeness to the sun.
Considerably closer and in plain view was the March 1226 conjunction of the two planets when Genghis Khan was conquering Asia. Monday s conjunction will be the closest pairing that is visible since way back then.