What’s the summer solstice? An astronomer explains it

The summer solstice marks the official starting of summer. It is the longest day and shortest night of the 12 months 88% of the world's population living within the northern hemisphere. Traditionally, the change of seasons is well known everywhere in the world with bonfires, festivals, etc. Music Festival.

Astronomers can calculate an actual time for the solstice when Earth reaches the purpose in its orbit where the North Pole is situated at 10:58 a.m. Eastern Time on June 21 of this 12 months. From Earth, the sun will appear farther north relative to the celebs. People living on the Tropic of Cancer, 23.5 degrees north of the equator, will see the sun pass directly overhead at noon.

In six months the sun will reach its southernmost point and omit the heads of the inhabitants of the Tropic of Capricorn, and northerners will experience the shortest days of the 12 months on the winter solstice.

The angle of the sun with respect to the Earth's equator changes so progressively near the solstices that the change is difficult to detect without instruments for about ten days. This is the origin of the word solstice, which implies “solar stop.”

This slow shift implies that June 21 is just a couple of second longer than June 19 in mid-northern latitudes. It will take about every week for the calculated amount of daylight to alter by greater than a minute. Even that’s an approximation: Earth's atmosphere bends light above the horizon by different amounts depending on the time, which may cause changes in sunrise and sunset times of greater than a minute.

The monuments of Stonehenge In England, Faculty in Egypt and Chankillo in Peru show that individuals all over the world have been tracking the sun's journeys north and south for greater than 5,000 years. From the stone circle of Stonehenge, the sun will rise on the solstice directly over an ancient avenue leading northeast. We know little concerning the builders of Stonehenge, or why they went to such trouble to construct it, transporting tons of stones from rocky outcrops 140 miles away.

All this to mark the purpose on the horizon where the sun returns every year to rest for some time before moving south again. Perhaps, like us, they celebrated this sign of the change of seasons.