Winter Solstice Time and Meaning As It Falls on Great Conjunction of Jupiter and Saturn

2020's winter solstice is a special one as it coincides with what is known as the great conjunction of Saturn and Jupiter, where the bright planets will form what has been dubbed a "Christmas Star" in the sky.

Below is everything you need to know about the two events happening on the same day.

What is winter solstice, and what time is it?

Winter solstice marks the shortest day of the year in the northern hemisphere, with the fewest hours of daylight and the longest night. This happens because the sun is at its southernmost point of the year. For the same reason, the December solstice is the first day of summer in the southern hemisphere.

This year's winter solstice is on December 21, and occurred at 5:02 a.m. Eastern Time.

How do people celebrate the Winter Solstice?

There are many celebrations spanning a variety of cultures around this time of year to mark the longest day. At the prehistoric Stonehenge monument in the U.K., for instance, people have gathered for thousands of years to watch the sun rise between its stones on both winter and summer solstice. The spectacle, usually observed by thousands of people at the site in Wiltshire, England, was streamed online this year due to COVID-19.

Nichola Tasker, Stonehenge Director, said in a statement: "The solstices and equinoxes are incredibly important moments in Stonehenge's calendar, but this year has not been kind to such gatherings."

In Iran people will be celebrating the Yaldā Night, a winter festival where people gather with loved ones to eat snacks like pomegranates, watermelons and nuts and read the poetry of Hafez. And in some parts of China, "Dongzhi" will be marked by families gathering to eat special meals; balls of rice called tangyuan in the south, and dumplings in the north.

stonehenge, winter solstice, stock, getty
A stock image shows the sun shining between the pillars of Stonehenge in the U.K. Winter solstice is celebrated at the prehistoric monument.

What is the great conjunction of Jupiter and Saturn, and what does it have to do with this year's winter solstice?

By chance, 2020's winter solstice falls on the same day as what is known as the great conjunction of the two planets in our solar system. Jupiter and Saturn align with one another (from our earthly vantage point) around once every two decades. But this time they will be passing closer than they have in nearly four centuries. What's more, this is the first time Saturn and Jupiter have aligned at night in 800 years. That means it will be visible almost anywhere on Earth according to NASA.

Due to its proximity to Christmas Day on December 25, the event has been dubbed the "Christmas star."

NASA astronomer Henry Throop said in a statement: "Conjunctions like this could happen on any day of the year, depending on where the planets are in their orbits.

"The date of the conjunction is determined by the positions of Jupiter, Saturn, and the Earth in their paths around the Sun, while the date of the solstice is determined by the tilt of Earth's axis. The solstice is the longest night of the year, so this rare coincidence will give people a great chance to go outside and see the solar system."