The Great Conjunction--December 21, 2020

The Great Conjunction--December 21, 2020

Approaching the winter solstice, there is also the Great conjunction of Jupiter and Saturn  on December 21.

You can read more about the Great Conjunction at

Jupiter takes less than 12 Earth years to complete an orbit around the sun.  Saturn takes more than 29 Earth years.  Every 20 years they come close to each other while revolving around the sun. 

This particular rendezvous will be the closest in nearly 400 years.   The last  Great Conjunction was in 1623! 

So, what was happening in 1623? According to Wikipedia--There was a plague in Malta. The Thirty Years War was going on. There were settlements in Plymouth, Massachusetts.  The first Folio of Shakespeare was published.  Pedro Calderón de la Barca's first play was presented at the Court of Hapsburg Spain.

It was the time of the Scientific Revolution.

Johannes Kepler was alive. He formulated the laws of planetary motion. Galileo was alive.  Among his many contributions to science and astronomy are that the earth revolves around  the sun.  He studied  the rings of Saturn. He discovered the four major moons of Jupiter--Io, Europa, Ganymede and Callisto.

It was also the time of the Holy Inquisition. The ideas of Galileo and Kepler would have been considered heresy.

Rene Descartes was alive. His statement "I think, therefore I am" is still a revolutionary idea. We are thinking, exploring, questioning beings. We too are living in  historic times.  May we see the light of enlightenment, the meeting of Saturn and Jupiter, the increasing light in days to come.

And here is Gustave Holst--Jupiter--played by the Chicago Symphony Orchestra.



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  • But (the real great conjunction) Galileo was imprisoned by the Catholic Church, and neither the Lutherans nor the Catholics had much use for Kepler. So, no "would have been" in either case.

    Is there a chance of seeing anything here, with all the streetlights and fog?

  • In reply to jack:

    Thanks for reading, Jack. I apologize for the phrasing. I should have been more clear.

    According to, the 1623 conjunction would have been hard to see from Earth, because it appeared so close to the sun. This time, Saturn and Jupiter can be seen near the southwest horizon an hour after sunset. You can look for them, now, if you can find an unobstructed view, away from bright lights. Binoculars or a telescope would give you the best view.

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