The Winter Solstice, which marks the beginning of winter, occurs on Thursday, December 21 at 11:28 a.m. Eastern Time. At that moment, the Sun will be as far south as it ever gets in our sky; and the day will see the shortest amount of daylight and the longest night of 2017. The Sun’s rays are concentrated on the Southern Hemisphere, where the Solstice marks the first day of summer, and the Sun shines straight down on the so-called Tropic of Capricorn at 23.5-degrees south latitude.
Does The Sun Stand Still?
As “armistice” is defined as a staying of the action of arms, “solstice” is a staying of the Sun’s apparent motion over the latitudes of the Earth. At the summer solstice, the Sun stops its northward motion and begins heading south. At the winter solstice, it turns north. Technically, even at 11:29 a.m. EST, the Sun has turned around and started north. It will cross the equator at the vernal equinox, passing into the Northern Hemisphere on March 20, at 12:15 p.m. EDT, when we will greet the spring season.
Fun Fact: Be sure to look at your noontime shadow around the time of the Winter Solstice — it’s your longest noontime shadow of the year.
Among the many varied customs linked with this special season for thousands of years, the exchanging of gifts is almost universal. Mother Nature herself offers the sky observer in north temperate latitudes these two gifts: longer nights, and a sky more transparent than usual.
One reason for the clarity of a winter’s night is that cold air cannot hold as much moisture as warm air can. Hence, on many nights in the summer, the warm moisture-laden atmosphere causes the sky to appear hazier. By day it is a milky, washed-out blue, which in winter becomes a richer, deeper and darker shade of blue.
For us in northern climates, this only adds more luster to that part of the sky containing the beautiful wintertime constellations such as Orion, the Hunter, and Taurus, the Bull. Indeed, it is seemingly Nature’s holiday decoration to commemorate the winter solstice and enlighten the long cold nights of winter.