Today people living in the Northern Hemisphere have woken up from the longest night of 2016. The winter solstice marks the first day of the “astronomical winter,” which is the day with the fewest hours of sunlight in 2016. The solstice happened at 5:44 a.m. Eastern Time on Wednesday when the tilt of the North Pole was -23.5 degrees outwards, furthest away from the Sun.

Winter solstice
Image Credit: fdecomite / Flickr

The shortest day of the year

While ‘astronomical winter’ begins with the winter solstice, meteorologists consider December 01 to be the start of winter season. Though an entire day is considered solstice, scientists can calculate the precise moment it occurs. The solstice occurs when the Sun is directly over the latitude line marking the Tropic of Capricorn, which runs through Australia, Chile, south Brazil and northern South Africa, according to Live Science.

According to EarthSky, the Northern Hemisphere has the shortest day of the year on winter solstice. The word solstice means “Sun stands still” in Latin. On this day, the Sun reaches its southernmost position in the Northern Hemisphere sky. After that, the Sun reverses its direction.

Does winter solstice always occur on Dec.21?

In the run up to the winter solstice, the days have been getting shorter and shorter for months in the Northern Hemisphere. Now the days will stop getting shorter. However, it doesn’t mean temperatures would go up immediately. The northern mid-latitudes will continue to experience winter chill because they will get only about nine hours of daylight for several weeks following the solstice. They get around 15 hours of daylight on the summer solstice.

The solstice usually falls on December 21st. But time varies each year due to the discrepancy between the solar time and the time we use. The variation is rectified once every four years when we get an extra day in February. It’s because of this variation that the winter solstice took place on December 22nd in 2015. The solstice can also occur on Dec.20, 22, and 23. But Dec.20 and 23 are extremely rare. The last Dec.23 solstice took place in 1903, and it is unlikely to happen before 2303, reports The Telegraph.

Winter solstice in ancient cultures

Cultures throughout history have recognized the winter solstice. In Mexico’s Yucatan Peninsula, the ancient Mayan city of Tulum has a structure honoring the summer and winter solstices. As the Sun rises on the solstice, its rays pass through a small hole at the peak of a stone building, creating a starburst effect.

In the UK, people gather at the ancient monuments of Stonehenge to witness the sunrise on the shortest day of the year. When the sun sets, its rays align with the central Altar stone and the Slaughter stone. Archaeologists believe that people who constructed the Stonehenge about 5,000 to 6,000 years ago, gave more importance to winter solstice than the summer solstice.

Photo by fdecomite