You hear the word solstice all the time. We have the summer solstice coming up on Saturday, June 20, 2020 and in a few months, the winter solstice (Monday, December 21) will be here, too. In the southern hemisphere, it’s the opposite: our summer solstice is their start of winter. So, what exactly do the solstices signify, and why do they matter?
For one, these events occur when the sun reaches its highest point in the sky by noon (summer) and inversely, when it reaches the lowest point in the sky at the same time (winter). They mark the start of two of the four seasons and have influenced the culture and customs of ancient empires including the Romans, Greeks, and Chinese. Here’s everything else you need to know about solstices.
What Is a Solstice?
The word solstice is a Latin derivative of two words: sol (sun) and sistere (stop, to be still). A solstice is defined as an event when the sun is at its highest or lowest point in the sky. This happens twice a year, and the occurrence of the summer and winter solstices marks the longest and shortest two days of the year, respectively.
While solstices are sometimes confused with equinoxes, they’re not the same thing. Solstices and equinoxes share similarities, like the fact that they’re both ruled by the equator’s distance from the sun during each season.
What Is an Equinox?
Equinox comes from the Medieval Latin word equinoxium, which fuses aequus (equal) with nox (night).
An equinox occurs when the sun lines up so that the equator bisects it. The occurrence gives us a day that is equal parts daytime and nighttime. This signals the beginning of spring (the vernal equinox) and fall (the autumnal equinox) each year. During an equinox, the sun is closest to the equator.
How Do Solstices Work?
The science that explains solstices has everything to do with Earth’s 23.5-degree obliquity (its axial tilt) as it orbits the sun. When the North Pole is closest to the sun, the northern hemisphere experiences summer. This lasts until the North Pole moves far enough away from the sun and we get winter.
In other words, the northern hemisphere gets the most amount of sunlight during the day between spring and fall until the sun reaches its peak in late June and gives us the summer solstice. During this time, the southern hemisphere experiences winter. The cycles repeat every year as Earth rotates on its axis and orbits the sun.
Why Do Solstices and Equinoxes Matter?
Solstices and equinoxes are responsible for the change in seasons we experience every year. (You can thank the autumnal equinox for the Pumpkin Spice Latte.) But these events aren’t just for changes in seasonal coffee flavors; they also have rich interpretations across various cultures throughout history.
Some estimates have humans observing solstices as early as the Stone Age (~2.5 million years ago) while others posit that neolithic humans used the summer solstice as an indicator for planting and harvesting crops.
Solstices have been celebrated across cultures that span the globe including in ancient China, where the summer solstice was revered as “Yin”—half of the dual philosophical concept of Yin and Yang—and ancient Greece, where the summer solstice signified the upcoming Olympic Games.
Meanwhile, European Pagans welcomed it by lighting bonfires and Native American tribes, such as the Sioux, would greet it with a ritual dance around a tree.
Solstices are also associated with and celebrated in Pagan religions; the winter solstice (“Yule”) has similar elements to Christmas celebrations, such as gift giving and meal sharing. Wiccans also observe Yule to celebrate the return of the Hunter God, who is sometimes depicted as the Norse God, Odin, and in other iterations, appears as Dionysus or Pan.
In Sweden, the summer solstice is called “Midsommar,” and it’s one of the most widely observed holidays where revelers, adorned with flower crowns and ribbons, dance around a maypole to celebrate love, life, and good fortune.
Then there’s Stonehenge in England, which was built in a way that lines up perfectly with both the summer and winter solstices. Although some speculate that the site was built as an alien aircraft landing zone, it’s more likely that it was created to mark the passing of time.
Stonehenge attracts thousands of tourists every year, who all come to witness the summer solstice, which is marked by the rising sun aligning with the Altar, Slaughter, and Heel Stones. Solstices aren’t just restricted to Earth, either. All planets in our solar system sit at a tilt, so they each experience their own seasons thanks to solstices and equinoxes.
