5 things you may not know about this phenomenon

Over the course of the weeks, and most of the time completely imperceptibly, the sun returned to its quarters. And here today is the one for us, in the northern hemisphere, the longest day of the whole year. Astronomers call it the summer solstice. It marks the beginning of the summer season – because the meteorological season begins on the first day^any June every year. But this, everyone knows.

The date of the summer solstice varies over the years

What we may know a little less is that the summer solstice in the Northern Hemisphere does not always fall on June 21st. As a result of small differences in the Earth’s orbit around the Sun. But also the organization of our calendar, with its leap years.

in XX^H Century, the summer solstice occurred 64 times on June 21 and all the same 36 times on June 22. regarding st^H Century, forecasts announce 47 summer solstice on June 20 and 53 on June 21. For it to fall on June 19, it will be necessary to be patient. That won’t happen until 2488.

This year, the summer solstice, the moment when the sun reaches its highest point in the sky (not its zenith), with respect to France, will happen this Wednesday, June 21 at 4:57 p.m. very accurate.

The day when the sun stands

Perhaps the origin of the term solstice is something else that we don’t know. It dates back to the thirteenth century^H a century. We inherited it from Latin floor about the sun and Gazing to stop. Because we must remember that our ancestors did not know why the daytime star rose and fell in their sky throughout the year. They thought it was a matter of good or bad. So when they saw him climb, they could only hope his run would stop. They will eventually descend and herald the start of the harvest season. And that is, science tells us, what it will continue to do for billions of years. At the time of the solstice…

The day when the earth occupies a special place in its orbit

Another thing that is not only generally ignored, but also seems completely counterintuitive to us inhabitants of the Northern Hemisphere: the summer solstice corresponds to the day when the Earth, in its orbit, is almost at aphelion, that is to say, farthest from our sun! About 152 million km. If today marks the beginning of summer, it has nothing to do with our planet’s position in space, but more with its inclination in its orbit. It directs the northern hemisphere “Face” In the sun.

The day of the solstice is not always very long

At the time of the summer solstice, Parisians can soak up the sun around 4:10 p.m. It is undoubtedly the longest day of the year. But its length may vary somewhat from year to year. A question of anisotropy in mass distributions on the Earth’s surface. As a result, scientists estimate that the longest day since the 1830s must have occurred on the summer solstice of 1912. This is difficult to realize, since it would last no more than 4 milliseconds longer than average.

Average does not take into account the special situation of regions located at high latitudes. In fact, in the Arctic Circle, the day of the solstice is also the day of the midnight sun. 24 hour day. On the North Pole side, on that day, the sun actually settles high in the sky at about 23 degrees.

Summer solstice, a day of celebration

Finally, this date of the summer solstice is so special that, since the dawn of time, traditions have celebrated it all over the world. Regardless of cultures and religions. The festivities were primarily pagan. We celebrated the harvest. Then some religions made it a feast of light. This is the symbolism of Saint John’s Day.

Even today, many people celebrate this day, dancing in the woods, wearing sometimes improbable costumes, lighting bonfires or… celebrating with music!