Thursday marks the winter solstice in the Northern Hemisphere — the shortest day of the year and the longest night of the year that serves a reminder that brighter days with more sunshine are ahead.
“The winter solstice occurs at the moment the Earth's tilt away from the sun is at a maximum,” Stephen Schneider told CBS News.
While the earth’s rotation pattern is predictable, winter solstice doesn’t occur on the same day every year. The solstice is actually a moment in time -- this year at 11:28 a.m. Eastern Time. It falls between Dec. 21 and 22, and occasionally Dec. 20 or Dec. 23 because modern calendars don’t match the solar year, according to the Weather Channel.
The winter solstice, also known as Yule, Midwinter, marks the beginning of the astronomical winter, but it’s not the coldest day of the year. Meteorologists at the Weather Channel argue that winter should actually start Dec. 1, representing the four coldest months in the northern hemisphere.
Contrary to popular belief, the winter solstice isn’t the earliest sunset of the year. According to EarthSky.org, the earliest sunset of the year falls between Nov. 29 and Dec. 9 in the United States.
The arctic region sees no sunlight on the day of the winter solstice.
Why the 2017 solstice is different
Some astrologers are concerned about the 2017 winter solstice because it coincides with two other major events – the end of Mercury retrograde and the first day the sun exits Sagittarius, Newsweek reported.
Astrologer Susan Miller told Newsweek that people should “take it easy” on Dec. 21 and not make big decisions or begin long trips, which is unsettling news considering millions are starting their Christmas vacation today.
But many are still celebrating the ancient event that has been a tradition in cultures throughout history including Rome and Scandinavia, according to BBC. Even the Christmas tree might have roots celebrating the solar event.
Stonehenge, a monument outside of London, hosts one of the world’s largest winter solstice celebrations, according to National Geographic. The Stonehenge monument is shaped so it aligns with the winter’s solstice sunset.