Tomorrow will be the shortest day of the year or the "winter solstice"; those in the Northern Hemisphere can look forward to more daylight in the near future.
"It's kind of a gut thing. People don't like the dark," Deborah Byrd, editor in chief of EarthSky.org. told USA Today. "After Christmas, you start to notice that the sun is setting later. Even a few minutes later is such a relief."
At exactly 12:11 p.m EST on Dec. 21 the Sun will be directly overhead and the North Pole will be at its maximum tilt from the Sun; meaning northerners will get to see the Sun perform its "lowest and shortest arc across the southern sky," the Washington Post reported.
The Sun moves northward across the equator on March 21 and southward on Sept 21, these occurrences are referred to as the ""equinoxes," Space.com reported. The word comes from Latin, and means "equal night" because the day and night are about the same length.
In the solstice on Dec. 21 the southward moving Sun will take a short break before moving northwards again. The "pause" is called the "solstice," which comes from the Latin word for Sun. The dates to slightly vary occasionally due to leap years.
Humans have focused on these four events since the dawn of farming. Stonehenge was believed to have been built as an "astronomical observatory" where one could track the movement of the Sun, Space.com reported.
"Culturally, the solstices and equinoxes are typically used to denote either the beginnings of the seasons or the center points of the seasons," Rick Kline, of the Spacecraft Planetary Imaging Facility at Cornell University in, said. "Christmas, Hanukkah, Kwanzaa and other holidays have arisen out of the solstices, equinoxes and the midpoints between them."
Some cultures have age-old traditions surrounding the solstice. In China the emperor at the time would offer sacrifice at the Temple of Heaven in Beijing during the solstice to "reassure" the Sun rose once again after the celestial event.
There is a reason for why the solstice and Christmas sync up.
"First, we don't really know when Christ was born, it's that simple," Edwin Krupp, director of the Griffith Observatory in Los Angeles, said. "It had its antecedents in Rome, which already had a celebration called Dies Natalis Solis Invictus, the Birthday of the Unconquerable Sun."
