Today will be the longest day of this year in the northern hemisphere, and the shortest day in the southern hemisphere, thanks to the summer solstice. The astronomical phenomenon is caused by the earth's axial tilt, which is the highest on this day. Summer solstice happens twice in a year, once for each hemisphere. On these days, one of the earth's poles has the maximum tilt towards the sun.
So, for that hemisphere, it is the day with the longest period of daylight. The other hemisphere has the lowest daylight duration that day. According to NASA, the word “solstice” in Latin means “Sun stands still.”
Why is June 21 longest day of the year in India?
Earth rotates once every day on its axis, an imaginary line connecting the North Pole and the South Pole. While this axis remains the same, the axial tilt of the planet changes as it moves in its orbit around the sun. Due to this, the North Pole is tilted towards the sun for six months the South Pole for the remaining six months.
Impact of the summer solstice
During the summer solstice, the rays of the sun strike the northern hemisphere at a more direct angle, resulting in prolonged daylight. One of the major effects is an increase in solar energy during the day since the sun is directly overhead.
Summer Solstice Celebrations
The summer solstice has been observed and commemorated by several cultures. The most well-known ancient location linked with the solstice is Stonehenge in England. The Heel Stone at Stonehenge is in line with the sun's beams as it rises on the longest day of the year. The event is streamed live on the official English Heritage YouTube channel -- link here.
In Sweden, the summer solstice is celebrated to welcome summer. People huddle around maypoles decorated with flowers and celebrate summer with songs and dance. The Midsummer date is also an officially declared holiday in Sweden.
Since Iceland enjoys 24 hours of daylight each day, summer solstice there is known as the Midnight Sun.
In Russia, summer solstice marks the White Night celebration. Musical performances, water events and fireworks mark the celebrations.
In Norway, summer solstice celebrations are known as Slinningsbalet, where bonfires are lit to commemorate the birth of John The Baptist. As per their beliefs, the fires purge the air of bad spirits.