CHENNAI: The winter solstice, a spectacular celestial event marking the shortest day and the longest night of the year, is to take place on Saturday (December 21). This annual event determines the seasons of each region and impacts how sunlight is distributed across the planet.
In India, the solstice will fall at 2.49 pm on December 21. The December solstice also heralds the start of winter in the Northern Hemisphere, lasting until the vernal equinox in March.
The winter solstice happens because of the earth’s axial tilt. The earth’s axis is tilted about 23.4 degrees away from the sun. During the December solstice, the north pole is at its furthest tilt away from the sun, while the south pole is tilted closest to it. This alignment causes the Sun’s rays to fall directly over the Tropic of Capricorn (23°27′ S).
In six months, during the summer solstice, the Sun's rays will align over the Tropic of Cancer (23°27′ N), marking the start of winter in the Southern Hemisphere.
While the Northern Hemisphere experiences its longest night today, the Southern Hemisphere celebrates the longest day of the year.
This fascinating event holds deep meanings within cultures and scientific studies all around the world. Historically, the winter solstice has been a time of rebirth and renewal across different cultures. Festivals like the Yule, which predated celebrations like Christmas, symbolised hope and the gradual return of longer days and brighter skies.