This Monday, December 21st, the southern hemisphere will live the longest day of the year and therefore the shortest night. The solstice marks the beginning of summer, a date long venerated by ancient cultures. This year, the exact time when the sun is vertical in the Tropic of Capricorn, time of solstice or quiet sun, is at 7:02 am (Brasília time). This date is usually one of the hottest of the year, especially in Rio de Janeiro. In the northern hemisphere, cycles are just the opposite: it is the beginning of winter with the shortest day and the longest night.
The summer solstice is the time of year when the sun reaches its highest or lowest apparent height in the sky, according to the hemisphere, the durations of the day or night are the maximum of the year. If the phenomenon does not occur on the same day and at the same time each year, it is because the Earth’s orbital period takes 365, 2425 days, a difference that the calendar makes up for with a leap every four years.