The Summer Solstice is an event in the Northern Hemisphere that marks the official start of summer. Normally this happens on June 21, but this year this event occurred on June 20 at 9:32 p.m. Mountain Daylight Time. People will often refer to the Summer Solstice as the longest day of the year. While technically all days are the same length, we generally are referring to that this is the summer day with the most amount of daylight hours and the shortest about of nighttime.
Due to the tilt of the Earth’s axis, the path of the sun appears to move north and south during the year. Each sunrise and sunset will occur at a slightly different position on the horizon. At the time of the solstice, the sun has reached its most northern position in the sky and for a few days, the location of the rising and the setting of the sun will be in the same spot. After the summer solstice, the path of the sun will begin to gradually move towards the south and our daylight hours will slowly begin to shorten. For folks living in the Southern Hemisphere, just the opposite is happening, and they are experiencing the start of winter with their daylight hours being the shortest.
For many cultures, the Summer Solstice was used as a way to measure time and they had built structures to precisely line up with the sun during both the Summer and Winter Solstice. Many Mayan and Aztec structures in Mexico and South America have features that demonstrate this ancient method of tracking time. One of the most famous structures built around the sun and shadows of the solstices is the ruins of Stonehenge in England.