Longest Day of the Year

• Author: admin
• Filed under: Gadgets
• Date: Jun 20,2008

On or around June 21 each year, the rays of the sun will be perpendicular to the Tropic of Cancer at 23°30′ North latitude. This day is the summer solstice in the Northern Hemisphere.

On this day, the earth’s “circle of illumination” will be from the Arctic Circle on the far side of the earth (in relation to the sun) to the Antarctic Circle on the near side of the earth. The equator receives twelve hours of daylight, there’s 24 hours of daylight at the North Pole and areas north of 66°30′ N, and there’s 24 hours of darkness at the South Pole and areas south of 66°30′ S.

June 20-21 is start of summer in the Northern Hemisphere but simultaneously the start of winter in the Southern Hemisphere. It’s also the longest day of sunlight for places in the Northern Hemisphere and the shortest day for cities south of the equator.

However, June 20-21 is not the day when the sun rises earliest in the morning nor when it sets latest at night.
Every June 21st hundreds of people go to Stonehenge to watch the sun rise. The sun shines on one famous stone - the Heel stone. For the Druids this is a very important moment of the year.

Druid celebrations also take place on Midsummer’s Eve. Bonfires are lit to show respect for the Sun God, whose power is greatest at the Summer Solstice. The fires also represent an attempt to ward off the coming winter. Practice of this ancient ritual, which also includes a Summer Solstice Circle Dance, is now mainly confined to Cornwall, the West Country, and London’s Hampstead Heath.
The two solstices can be distinguished by different pairs of names, depending on which feature one wants to stress.

* Summer solstice and winter solstice are the most common names. However, these can be ambiguous since seasons of the northern hemisphere and southern hemisphere are opposites, and the summer solstice of one hemisphere is the winter solstice of the other.
* Northern solstice and southern solstice indicate the direction of the sun’s movement. The northern solstice is in June on Earth, when the sun is directly over the Tropic of Cancer in the Northern Hemisphere, and the southern solstice is in December, when the sun is directly over the Tropic of Capricorn in the Southern Hemisphere.
* June solstice and December solstice are an alternative to the more common “summer” and “winter” terms, but without the ambiguity for which hemisphere they are intended. They are still not universal, however, as not all people on Earth use a solar-based calendar where the solstices occur every year in the same month (as they do not in the Hebrew calendar, for example), and the names are also not useful for other planets (Mars, for example), even though these planets do have seasons.
* First point of Cancer and first point of Capricorn. One disadvantage of these names is that, due to the precession of the equinoxes, the astrological signs where these solstices are located no longer correspond with the actual constellations.
* Taurus solstice and Sagittarius solstice are names that indicate in which constellations the two solstices are currently located. These terms are not widely used, though, and until December 1989 the first solstice was in Gemini, according to official IAU boundaries.
* The Latin names Hibernal solstice (winter), and Aestival solstice (summer) are sometimes used.
June 21 is called the summer solstice in the Northern Hemisphere and simultaneously the winter solstice in the Southern Hemisphere. Around December 21 the solstices are reversed and winter begins in the northern hemisphere.

On June 21, there are 24 hours of daylight north of the Arctic Circle (66.5° north of the equator) and 24 hours of darkness south of the Antarctic Circle (66.5° south of the equator). The sun’s rays are directly overhead along the Tropic of Cancer (the latitude line at 23.5° north, passing through Mexico, Saharan Africa, and India) on June 21.

Technorati Tags: summer solstice, summer solstice 2008, summer equinox, first day of summer, solstice