Summer solstice, because the summer season begins today

Summer solstice

June 21 is the summer solstice, the longest day of the year and the beginning of the astronomical summer. Let's see what it is

(photo: Getty Images) Ready to enjoy the longest day of the year? June 21 is the summer solstice, the day when the Sun reaches its northernmost point (i.e. higher than the horizon) in its annual run in our skies, giving us the maximum number of hours of light possible in the span of a day. Today's date also marks another appointment: the official start of summer. From 22 June, in fact, the peak of the Sun will again begin to move further and further south, and the days, which until now had progressively lengthened, will inexorably start to shorten again, marking the time of year that scientists define as astronomical summer. and which will end around 21 December with the winter solstice.

Solstices and equinoxes are due to the trajectory with which our planet orbits the Sun. The axis of rotation of the Earth and the plane of the orbit are not in fact perpendicular, but instead meet at an angle of about 23.5 degrees, an asymmetry that from the Earth generates the apparent motion of the Sun in the skies during the course. of the year. In our hemisphere therefore, throughout the winter the Sun rises a little more than the previous day with respect to the horizon, reaching its maximum height - at least this year - on 21 June at 3:32 UTC (for the Italy at 5:32), to then begin its inexorable descent, which will end on 21 December, when the cycle begins again.

The axis of rotation of the Earth and the plane of the orbit are not perpendicular In the southern hemisphere, however, the situation is reversed: June 20/21 is the shortest day of the year, while the 21/22 December is the longest. The solstices are therefore all a matter of perspective. If during the summer solstice you were for example near the Tropic of Cancer, the Sun would rise until it is exactly perpendicular above your head when it reaches the highest point in the sky (the so-called astronomical noon). If you were instead at the Artic Polar Circle, the Sun would never set for the whole day, while at the Antarctic Polar Circle it would be dark for all 24 hours.

During the summer solstice, along the Tropic of Cancer the Sun rises to be directly perpendicular to an observer during astronomical noon (photo: Nasa) For millennia, the summer solstice has been considered a special day by many civilizations of the past. For example, it is believed that among the reasons that led to the construction of the stone circle at Stonehenge there was precisely that of paying homage and studying the solstices and equinoxes, and that the ordering of the stones is thought to align with the first sun on the day of the summer solstice. It would have been precisely the importance that the date had. Between 20 and 21 June falls the summer solstice, the longest day of the year and the beginning of the astronomical summer. Let's see what it is for the pagan civilizations to motivate the choice of June 24 as the day of birth of St. John the Baptist (exactly six months after Jesus Christ, born in conjunction with the winter solstice), so as to bring back the celebrations in the context of the Christian faith.

The solstice, as a midsummer festival (celebrated in the days ranging from 21 to 25) is also still today an important holiday in many European countries, such as Sweden (where in the past it was thought to officially transform it into the national holiday), R omania, Poland, U craina, the U nite Kingdom, Spain, Portugal and Greece. In short, only in Italy of the summer solstice, or the feast of St. John the Baptist, if you prefer, we are of little interest, since we prefer to celebrate the summer in mid-August.


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