20 Jun 2024

The dates June 20-21 will forever be significant in the astronomical calendar as it marks the annual solstice of the sun to the earth.

For all of creatures on earth, nothing is so fundamental as the length of the day and night.

After all, the sun is the ultimate source of almost all light and warmth on earth surface and for countries in the  Southern  hemisphere - Botswana  included - the period between  June  20-21  would experience the  shortest days  and the longest nights  which is referred to  as  the June  solstice.

The Principal Meteorologist with the Department of Meteorological Services, Mr George Keotsene told BOPA that the ‘Solstice’ means the sun has gotten as high in the sky as it is going to get for the year.

“This simply means that  we are expecting an early sun set and a later  sunrise south of the equator, while  the northern hemisphere will have the longest daylight hours,” he said.

He highlighted that  solstices were  a results of the sun’s  movement around the  earth, adding that the  earth had seasons because it is tilted, so light from the sun changes throughout the year differently for different parts of the world.

“During a year, the sub-solar point which  is  the spot on the earth’s surface directly beneath the Sun, slowly moves along a north-south axis. Having reached its southernmost point during the December solstice, it stops and starts moving northward until it crosses the equator on the day of the March equinox. At the June solstice, which marks the northernmost point of its journey, it stops again to start its journey back toward the south,” he explained. 

He said in the months leading up to the June solstice, the position of sunrise and sunset creeps northward of the equator and it reaches its northernmost point on the day of the solstice and thereafter, the daily path of the sun across the sky begins to creep southward again which would  slowly  lead to  longer  days  in Botswana.

Mr Keotsene said solstices occurred twice every year in June and in December citing that Botswana normally  experienced solstices on June 20-21  and December  22-23.

Additionally, Mr Keotsene indicated there was no peculiarity about this years’ June solstice contrary to the public belief that the night would  be the longest in history. Ends