The Christmas night sky: A 2021 Yuletide stargazing guide

Christmas is almost here, and the night sky obliges by presenting a beautiful display of celestial sights, perfectly timed out to coincide with the holiday.

In ancient times, Dec. 25 was the date of the lavish Roman festival of Saturnalia, a sort of bacchanalian Thanksgiving to the god of agriculture, for whom the slowest moving of the then-known planets was named. Saturnalia was celebrated on the date of the winter solstice by the calendar then in use, and it also marked the fact that the sun had stopped creeping southward in the noon sky and would thenceforth cross the meridian higher each day, warming the Earth and reawakening nature.