Winter Solstice: All you need to know about longest night of the year

The Winter Solstice, also known as midwinter, is an astronomical phenomenon marking the day with the shortest period of daylight and the longest night of the year.

Today Google doodle celebrates the first day of winter and the longest night of the year for the Northern Hemisphere, also known as the Winter Solstice. As our earth circles the sun, the North Pole angles farthest away from the sun today on December 21. 

The Winter Solstice, also known as midwinter, is an astronomical phenomenon marking the day with the shortest period of daylight and the longest night of the year. Winter solstice occurs when one of the Earth's poles has its maximum tilt away from the Sun. It happens twice yearly, once in each hemisphere. In the Northern Hemisphere, it is the December solstice.

Length of the day increases from the equator towards the South Pole in the Southern Hemisphere in December (around the summer solstice there), but decreases towards the North Pole in the Northern Hemisphere at the time of the northern winter solstice. Worldwide, interpretation of the event has varied across cultures, but many have held a recognition of rebirth, involving holidays, festivals, gatherings, rituals or other celebrations around that time

The winter solstice may have been a special moment of the annual cycle for some cultures even during Neolithic times. Astronomical events were often used to guide activities such as the mating of animals, the sowing of crops and the monitoring of winter reserves of food. Many cultural mythologies and traditions are derived from this.