Explained: The science behind why 21 June is the longest day of the year

The summer solstice is upon us today. On 21 June, the northern hemisphere experiences its longest day of the year, while the southern hemisphere experiences its shortest day. It is also where summer occurs in the middle of the year, as opposed to the southern hemisphere, when summer is in December, after half a year of arctic winter. After this day, the days gradually get shorter. So what is the underlying science of the longest day of the year? Let’s look more closely. Also read: Why has Earth’s pole moved? What’s the connection to India? The meaning According to NASA, the word “solstice” means “sun stands still” in Latin. This is due to the solstice having the furthest northeast sunrise and the furthest northwest sunset of the entire year. The sun also appears near these furthest places for a few days before and after the solstice before slowly moving back to rise and set due east at the following equinox. The science NASA explains that the seasons are indicated by the solstices and equinoxes, which are brought on by the Earth’s axis’ 23.5-degree tilt with respect to its orbit around the sun. Due to this tilt, depending on the season, various areas of the Earth receive sunlight for varying amounts of time. The Sun crosses the Tropic of Cancer on the day of the solstice, where it stops for a moment before turning around and going southward once more. The Tropic of Cancer, which lies about 23.5 degrees north of the equator and runs through Algeria, Niger, Libya, Egypt, Saudi Arabia, the United Arab Emirates, Oman, India, Bangladesh, Myanmar, China, Taiwan, Mexico, the Bahamas, Mauritania, and Mali, has a higher latitude where the noon sun is directly overhead, according to LiveScience. The phenomenon will occur this year on 21 June at 3:58 PM BST in the UK, 10:58 am ET / 7:58 am PT in the US, and 8:27 pm in India. It isn’t the warmest day According to the Royal Meteorological Society, the reason for the seasonal lag is that Earth’s land and ocean require some time to warm up. In the Northern Hemisphere, the days start to progressively shorter after the summer solstice. In comparison to the around nine hours of daily sunlight around the winter solstice, northern midlatitudes see about 15 hours of daylight in the weeks after the summer solstice. In addition, the Northern Hemisphere continues to be warmed by its tilt towards the sun. Also read: Manhattanhenge Magic: A rare and truly breathtaking sunset over New York The Earth’s distance from the sun During the summer, some regions of the Northern Hemisphere can become so hot that you could believe Earth is getting closer to the sun. Contrary to popular belief, according to timeanddate.com, Earth is closest to the sun during the summertime in the Northern Hemisphere. NASA says that the Earth’s distance from the sun is typically 93 million miles (150 million km). According to Almanac.com, Earth will be the furthest from the sun on 6 July 2023, at 4:06 pm EDT (1:36 am IST), when it will be 94,506,364 miles (152,093,251 kilometres) away. This is known as the aphelion. This is roughly two weeks following the June solstice. Similar to this, according to LiveScience, Earth will reach its perihelion, or closest point to the sun, on 2 January 2024, at 7:38 pm EDT (5:08 am IST), two weeks after the December solstice. At this time, Earth will be 91,404,095 miles (147,100,632 km) from our star. The date can vary The Northern Hemisphere’s summer solstice occurs every year on either 20 or 21 June, depending on the year. The summer solstice occurs in the Southern Hemisphere on 21 or 22 December. The Gregorian calendar contains 365 days, with an extra leap day added in February every four years, therefore the date fluctuates. According to NASA, the actual duration of Earth’s orbit around the sun is 365.25 days. The solstice doesn’t always fall on the same day because of this mismatch. Also read: Scientists reveal Earth has a new “moon” that will stay with us for at least another 1500 years Celebrations The summer solstice has been observed and commemorated by several cultures. The most well-known ancient location associated with the solstice is Stonehenge in England. The Heel Stone at Stonehenge is in line with the sun’s beams when it rises on the longest day of the year. On the official English Heritage YouTube channel, the event is streamed live. On the summer solstice, the sun seems to set between the historic pyramids of Khafre and Khufu as seen from the Sphinx at Giza, Egypt. The Summer Solstice is referred to as Midsommar in Sweden. To celebrate and welcome summer, people huddle around maypoles that they have decorated with flowers. Since Iceland enjoys 24 hours of daylight each day, the event is known as the Midnight Sun celebration and features, among other things, bonfires and displays that stay all night. The celebration, also known as White Night in Russia, is a grand occasion. Along with musical performances and a Scarlet Sails event, which sees enormous ships cruise across the Neva River with bright red sails, fireworks displays are on display. The festival is known as Slinningsblet in Norway, where bonfires are lighted to commemorate John the Baptist’s birth. According to legend, these fires purge the air of bad spirits. With inputs from agencies Read all the  Latest News ,  Trending News ,  Cricket News ,  Bollywood News , India News  and  Entertainment News  here. Follow us on  Facebook ,  Twitter  and  Instagram .