Google Doodle on Tuesday, 21 December, is celebrating the arrival of Winter season. The American tech giant shared an animated doodle of a hedgehog in the snow on its homepage to mark the day.
Google also shared a tweet saying "As the Earth tilts on its axis, many across the Southern Hemisphere prepare to chill out for the next few months. Happy first day of Winter!"
21 December is also known as December Solstice and it marks the beginning of winters in Norther Hemisphere. It also marks the shortest day and longest night of the year.
Solstices occur twice a year, i.e Summer and Winter. For Northern Hemisphere, as mentioned above, the Winter Solstice comes around 21 December, while Summer solstice occurs around 21 June.
What is December Solstice?
December solstice also known as Winter solstice is caused by the tilt of Earth’s axis and by its orbital motion around the sun.
According to EartySky, during December solstice, Earth, instead of orbiting upright, it is tilted on its axis by 23 1/2 degrees.
"Although the tilt of the Earth as compared to the plane of its orbit around the Sun is more or less constant (23.5˚), at the December solstice, the Northern Hemisphere receives the most indirect sunlight, causing cooler temperatures," reads the official blog of NASA.
During December solstice, all locations which are on the north of equator witness shorter days, i.e. less than 12 hours, and longer nights.
The winter season in northern hemisphere will go on till around 20 March, which marks the beginning of Spring.
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