Go to the EiE Blog homepage

The Science Behind Winter Solstice

Posted by EiE Team on Monday, December 21, 2020

What is Solstice?

Winter Solstice, the shortest day of the year in the Northern hemisphere, falls on December 21st and marks the official start of the winter season. On the same day, people living in the Southern hemisphere have their Summer Solstice and mark their longest day of the year! These days flip flop in June, when we have our longest day of the year and our first day of summer in the Northern hemisphere and the Southern countries move into winter.

The word “solstice” comes from the Latin words sol (sun) and sistere (to stand still) because, during the solstice, the angle between the Sun’s rays and the plane of the Earth’s equator (called declination) appears to stand still. 

What makes Solstice happen?

Winter solstice is an astronomical event where the sun reaches its southernmost latitude and can still be seen overhead, a point called the Tropic of Capricorn or Southern Tropic. This means, at noon, the sun is its lowest position in the sky it will reach all year, making our daylight hours short. 

You can watch a video of the winter solstice in Alaska, where there’s only daylight for less than four hours! 

Solstice Traditions

Many cultures have long celebrated solstice days - both summer and winter - with festivals, traditional foods and ceremonies. 

In Druidic tradition, Winter Solstice is seen as a time of rebirth when Nature’s powers are renewed. In Scandinavia, fires symbolize the heat, light and life-giving properties of the Sun, with a Yule log burned on the hearth in honor of the Scandinavian god, Thor. Even in ancient Rome, they celebrated a festival called Saturnalia for seven days to celebrate the shortest day of the year. 

With STEM learners, solstice is a great time to introduce key concepts like latitude, axis tilt and orbit and build on earth science and astronomy fundamentals. Get creative with a globe and flashlight to demonstrate how much light hits the Northern hemisphere as it moves through its orbit, or take a moment to implement STEM into your other lessons by going over solstice history. Any way you celebrate, we hope you have a happy solstice!

Written by EiE Team

Subscribe to Email Updates