Why do solstices happen

The Franklin Institute. The Current. Why Do We Have Seasons? Solstices Occuring in June and December, the solstice marks either the start of winter or the start of summer. Equinoxes Equinoxes happen directly between the solstices and mark the beginning of the Spring and Fall seasons.

Doug Ray As the former Social Media Manager for The Franklin Institute, Doug was responsible for the development and strategy behind social media outreach and a variety of other digital media activities for one of the most visited museums in the United States.

Earth is not the only planet with solstices and equinoxes; any planet with a tilted rotational axis would see them, too.

In fact, planetary scientists use solstices and equinoxes to define "seasons" for other planets in our solar system. It's worth noting, though, that other planets' seasons don't climatically equal those on Earth for a few reasons. First, planets vary in their axial tilts: Venus's axis of rotation is tilted by just three degrees, so there's much less seasonal difference between the Venusian summer and winter solstices than those on Earth.

In addition, planets such as Mars have less circular orbits than Earth's, which means that their distances from the sun vary more dramatically than ours do, with correspondingly bigger effects on seasonal temperature.

Earth makes its closest annual approach of the sun about two weeks after the December solstice , during the Northern Hemisphere's winter. Earth is farthest from the sun about two weeks after the June solstice, during the Northern Hemisphere's summer.

For millennia, cultures around the world have devised ways to celebrate and revere these celestial events—from building structures that align with the solstice to throwing raucous festivals in its honor.

Though the purpose of the enigmatic English structure Stonehenge remains unknown, this 5,year-old monument has a famously special relationship with the solstices. In Egypt, the Great Pyramids at Giza appear to be aligned with the sun as well.

When viewed from the Sphinx, the sun sets between the pyramids of Khufu and Khafre during the summer solstice—though it remains unclear precisely how the ancient Egyptians oriented it this way. Many cultures have found unique ways to mark the summer solstice. The traditional Scandinavian holiday of Midsummer welcomes it with maypole dancing, drinking, and romance. During the Slavic holiday of Ivan Kupala , people wear floral wreaths and dance around bonfires, while some plucky souls jump over the fires as a way of ensuring good luck and health.

In a more modern tradition, the people of Fairbanks, Alaska, swing in the summer solstice with a nighttime baseball game to celebrate the fact that they can get up to The Midnight Sun Game has been played times now since The winter solstice has had its share of celebrations, too. The festival is still celebrated throughout the Andes, and since , a reconstruction of Inti Raymi has been staged in Cusco, Peru, less than two miles from its Inca Empire home.

Ancient Romans celebrated the winter solstice with Saturnalia , a seven-day festival that involved giving presents, decorating houses with plants, and lighting candles. These correspond to midsummer and midwinter respectively, which are the turning points in the sun's journey. Once the sun reaches its zenith at the summer solstice, it will begin its journey toward the horizon, culminating in the winter solstice at its nadir.

In the weeks before these solstice turning points, the sun appears to move very little, earning it the name "sun standstill. Related: Saturn basks in sunlight in spectacular summer solstice view photo.

If you were to map the sun's midday position every day for a year, it would make a lopsided figure eight, called an analemma. The point at which the curves of the figure eight intersect is the equinox , which is when day and night are roughly equal in length. Humans have been observing the sun's position in the sky for thousands of years. Solstices have inspired religious rituals throughout the world, and people have built monuments to celebrate the event. At Stonehenge in the U. Researchers believe that solstices have been celebrated at Stonehenge for thousands of years.

The Seasons We all know that the Earth makes a complete revolution around the sun once every days, following an orbit that is elliptical in shape. The Relationship Between Length of Day and Temperature There is a lag between the longest day of the year and the warmest average temperatures for most mid and high latitude locations.

Current Weather. Forecast Maps. Hour by Hour Forecast. Winter Weather. Graphical Hazards. Text Bulletins. Marine Forecasts. Forecaster's Discussion. Submit Storm Report. Beach Forecast. Fire Weather. Follow us on Twitter.