Today is the Winter Solstice - Here's what it Means

Today, December 21st, is the Winter Solstice.   The winter solstice occurs when either of Earth's poles reaches its maximum tilt away from the Sun. This happens twice yearly, once in each hemisphere. Today we'll explore it. 

{Caption: How Earth's axial tilt and the sun work to create the December solstice, which marks the start of winter in the Northern Hemisphere. Shayanne Gal/Business Insider)

The winter solstice is also called the hiemal solstice or hibernal solstice. 

Earth orbits the sun once every 365 days and six hours and rotates once a day on a tilted axis.

That tilt is about 23.45 degrees (for now), and it bathes different parts of the world with various intensities of light over the course of a year. Meanwhile, Earth's rotation keeps the sun's heat even, sort of like a 7,917-mile-wide rotisserie chicken made of rock and a little water.

When the sun reaches its maximum distance north or south of the celestial equator. In the Northern Hemisphere, the day of the summer solstice (about June 21, marking the beginning of summer) is the time of the sun's maximum elevation and, thus, has the longest period of sunlight; winter solstice (about Dec. 21, marking the beginning of winter) is the time of the sun's minimum elevation and, thus, has the shortest period of sunlight.

Here's a brilliant video explanation from the BBC News in England: https://youtu.be/Xt-5GWexHIA