The sun rises above Emerald Bay on Lake Tahoe on the summer solstice. Credit: Beau Rogers (Flickr, CC By-NC 2.0)
Summer starts in the northern hemisphere on Friday 20 June at 10:42 pm of oriental legal hour. This annual event, known as the June solstice, marks a specific point in the terrestrial orbit. And it happens because our planet is inclined.
The earth maintains an inclination of about 23.5 ° on its axis. While the planet orbit the sun in orbit, this inclination causes several hemispheres to receive variable quantities of direct sunlight throughout the year. During the June solstice, the northern hemisphere is angled more directly towards the sun. Consequently, the sunlight reaches this region in its steep angle, bringing to the light day of the longest day during the year. For the positions located north of the Arctic Circle, this alignment translates into the phenomenon known as the “midnight sun”, where the sun remains visible all night. On the contrary, the southern hemisphere experiences its winter solstice right now, receiving the less direct sunlight and its shortest day of the year.
The term solstice Origi the Latin words “Sol”, which means sun and “sister”, which means to stay still. This refers to the apparent stationary position of the sun in its movement north (or south) through the sky for a few days before it begins to reverse its direction. If you look at the sun on the horizon several days before and after the solstice you will see few changes in its increases in increase and setting.
Just as a margin note, most people call this event the summer solstice. This is technically correct only for those of us who live in the northern hemisphere. South of the equator, it is the winter solstice. So, to prevent confusion, astronomers simply use the name of the month.
Historically, the June solstice was significant for various human cultures. The ancient civilizations, including the managers of the construction of Stonehenge in England, aligned structures to observe the position of the sun during the solstice. These alignments show that the ancient peoples have used the solstice as an indicator for calendars and temporal agricultural activities. Traditional celebrations and rituals often coincided with today, recognizing the change in the seasons. Modern interpretations continue to recognize the solstice as an indicator of the annual cycle and a seasonal transition point.
The June solstice provides a clear demonstration of the orbital mechanics of the earth and the axial inclination. It is a predictable astronomical event that underlines the dynamic relationship between our planet and the sun, influencing the cycles of daily light all over the world. It is not something that we can observe, but it is important, however. So, happy solstice!
