DECEMBER

SKY WATCH: We welcome winter with the "Great Conjunction," which unfolds every two decades and has been celebrated since ancient times. The Moon is near the two giant worlds of Jupiter and Saturn on the 16th and 17th. Then Jupiter passes extremely close to Saturn from the 20th to the 22nd, coming closest on the 21st—the solstice. So close are the two planets that they merge almost into a single "star," near enough to fit together in the same telescope field of view and very much visible with the naked eye. Look for them 45 minutes after local sunset, low in fading evening twilight, roughly 14 degrees above the southwestern horizon. Often too close to the Sun to be observable (as in 2000), this conjunction is truly great and not to be missed!

All times are given in Eastern Standard Time.

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