The December Solstice: Shortest and Longest Day of 2020
The December Solstice is coming, marking the beginning of a new season and bringing the shortest day of 2020 for the Northern Hemisphere and the longest one for those located in our planet's southern part. In today's article, we'll tell you all you need to know about the December solstice and some interesting facts about this astronomical event.
What is a solstice?
A solstice occurs when the Sun reaches its northernmost or southernmost point from the equator for the year, which is caused by the tilt of the Earth's axis and our planet's motion in its orbit around the Sun. The term "solstice" comes from Latin "sol" (Sun) and "sistere" (to stand still) and means "sun-stopping" as the Sun appears to stop moving in the sky and stand at its northernmost or southernmost declination during a solstice.
Two solstices occur each year: the summer and the winter ones. They take place around June 21 and December 21, respectively, but there are no fixed dates. Traditionally, solstices (and equinoxes) mark the beginning of a new astronomical season.
The December solstice
At the December solstice, in the Northern Hemisphere, the Sun reaches its lowest and southernmost point in the sky, while in the Southern Hemisphere, the Sun will be at its highest point in the sky on this day. Also, for those in the northern part of our planet, the December solstice brings the shortest day (the shortest period of sunlight/daylight) and the longest night; after the solstice in December, the days get longer and the nights shorter. In contrast, the longest day and the shortest night of the year come at the solstice in the Southern hemisphere.
The December solstice is called the southern solstice as the Sun shines directly overhead when seen from locations on the Southern Tropic (the Tropic of Capricorn) on this day at noon — this is the southernmost point that the Sun ever gets.
In 2020, the December solstice will occur on December 21 at 04:47 EST (09:47 GMT). The observers from both the Northern and Southern Hemispheres can see the year's southernmost sunrise and southernmost sunset. In the Northern Hemisphere, the December solstice is the winter solstice, which marks the beginning of astronomical winter in this part of the world. For the Southern Hemisphere, the December solstice is the summer solstice that brings the summer season.
See a rare “Christmas Star” on the December solstice
Note that this year the December solstice coincides with the great conjunction of Jupiter and Saturn — this rare and spectacular astronomical event will also take place on December 21. The gas giants will appear to almost merge in the night sky forming a brilliant “Christmas Star”. The Great Conjunction 2020 of Jupiter and Saturn will be the closest since 1623 and the closest observable since 1226!
Curious facts about the annual December solstice
- The December solstice can occur on December 20-23; however, the solstices rarely fall on December 20 or 23. The last solstice that took place on December 23 happened in 1903, and the next one will occur in 2303.
- Though it's winter in the Northern Hemisphere, the Earth is actually closest to the Sun during this period of the year. Our planet reaches its perihelion — the closest point to the Sun in its orbit — just a few weeks after the December solstice.
- On this day, the observers from the regions south of the Antarctic Circle towards the South Pole will see the Midnight Sun as they will have 24 hours of daylight. Meanwhile, those located north of the Arctic Circle will have 24 hours of darkness.
- Around the December solstice, many feasts and holidays are celebrated by people of various cultures. At the time of the December solstice, a pre-Christian festival known as the Feast of Juul (or Yule) was held in Scandinavia, while the ancient Romans celebrated the festival Saturnalia and the ancient Incas honored the Sun god Inti.
Take our fun and educational quiz about equinoxes and solstices! Check your knowledge of these two astronomical events and learn more interesting facts. See how many you can get right and share the result with your friends!