After all that has happened in 2020, the year will end with a beautiful, bright, star-like celestial event in the western twilight – a much-needed “candle in the dark”.
This rare event called a conjunction will bring two bright planets, Jupiter and Saturn, very close together in the sky.
Normally widely separated, on occasion they come within about 10 degrees of each other. For comparison, the two stars in the front of the “bowl” in the Big Dipper are 5 degrees from each other.
However, on December 21, the two planets will be only 6 minutes of arc apart. That is so close, some people will perceive them as a single brilliant star. For comparison, the moon is 30 minutes (half a degree) in diameter.
What will it look like?
Saturn will appear as close to Jupiter as some of Jupiter’s attendant moons. Attachment 1 shows what the two planets will look like through a small to medium size telescope:
Where will it be visible?
Look to the Southwest sky between 5:00 and 5:30pm. The sun sets at 4:30 so, unfortunately, the sky may not be completely dark. Jupiter and Saturn will then be 12 degrees above the horizon. Above and to the right, the bright star Altair can be used as a guide and on the left the half-full moon will be a third of the way up above the south:
All of this assumes that we in Salem, Oregon, will have clear skies. If not, not to worry, someone elsewhere in the world will photograph it and make it available to other astronomers. I will make sure that it is passed on to you.
-Nick
