Sky Watch: Week of December 20
The winter solstice, when fall ends and winter begins, will occur at 12:47pm Monday, Eastern time. At that moment, the Sun will be as far south as it is gets in our sky, bringing the day with the shortest duration of sunlight and, thus, the longest night. The Sun’s rays are concentrated on the Southern Hemisphere, where the solstice marks the first day of summer and the Sun shines directly on the Tropic of Capricorn, at 23 degrees 30 minutes south latitude. An “armistice” is a staying of the arms, “solstice” is a staying of the Sun’s apparent motion over the latitudes of the Earth. At our summer solstice, the Sun stops its northward motion and begins heading south. At our winter solstice, it turns north. Even at 12:48, the Sun will have ended its southern journey and started north. It will cross the equator at the vernal equinox, passing into the Northern Hemisphere at 12:32pm on March 20.
NYT, Joe Rao