The summer solstice (or estival solstice), also known as midsummer, occurs when a planet's rotational axis, or geographical pole on either its Northern or its Southern Hemisphere is most greatly inclined toward the star that it orbits. On the summer solstice, Earth's maximum axial tilt toward the Sun is 23.44°. (Likewise, the Sun's declination from the celestial equator is 23.44°.) This happens twice each year (once in each hemisphere), when the Sun reaches its highest position in the sky as seen from the North or South Pole
The summer solstice occurs during the hemisphere's summer. This is the June solstice in the Northern Hemisphere and the December solstice in the Southern Hemisphere. Depending on the shift of the calendar, the summer solstice occurs some time between June 20 and June 22 in the Northern Hemisphere and between December 20 and December 23 each year in the Southern Hemisphere. The same dates in the opposite hemisphere are referred to as the winter solstice.
As seen from a geographic pole, the Sun reaches its highest altitude of the year on the summer solstice. The colloquial term "midsummer" refers to the day on which the solstice occurs. The summer solstice day has the longest period of daylight, except in the polar regions, where daytime remains continuous for 24 hours every day during a period ranging from a few days to six months around the summer solstice.
Video Summer solstice
Distinctions
Although the summer solstice is the longest day of the year for that hemisphere, the dates of earliest sunrise and latest sunset vary by a few days. This is because the earth orbits the sun in an ellipse, and its orbital speed varies slightly during the year. See the Equation of time for details. Although the sun appears at its highest altitude from the viewpoint of an observer in outer space or a terrestrial observer outside tropical latitudes, the highest altitude occurs on a different day for certain locations in the tropics, specifically those where the sun is directly overhead (maximum 90 degrees elevation) at the subsolar point. This day occurs twice each year for all locations between the Tropic of Cancer and Tropic of Capricorn because the overhead sun appears to cross a given latitude once before the day of the solstice and once afterward. For example, Lahaina Noon occurs in May and July in Hawaii. See solstice article. For all observers, the apparent position of the noon sun is at its most northerly point on the June solstice and most southerly on the December solstice.
Maps Summer solstice
Full moon
2016 was the first time in nearly 70 years that a full moon and the Northern Hemisphere's summer solstice occurred on the same day. The 2016 summer solstice's full moon rose just as the sun set.
Cultural aspects
The significance given to the summer solstice has varied among cultures, but most recognize the event in some way with holidays, festivals, and rituals around that time with themes of religion or fertility. In some regions, the summer solstice is seen as the beginning of summer and the end of spring. In other cultural conventions, the solstice is closer to the middle of summer.
Solstice is derived from the Latin words sol (sun) and sistere (to stand still).
Date
Celebrations
- Day of Private Reflection (Northern Ireland)
- Fremont Solstice Parade (Fremont, Seattle, Washington, United States)
- Guru Purnima (India)
- Christmas typically marks the southern summer solstice.
- International Surfing Day
- International Yoga Day
- Juhannus (Finland)
- J??i (Latvia)
- Midsummer
- National Aboriginal Day (Canada)
- Tireg?n (Iran)
- World Music Day
Winter solstice in the Southern Hemisphere
- Inti Raymi, Machu Picchu, Peru
- We Tripantu, (Mapuche, southern Chile)
- Willkakuti, an Andean-Amazonic New Year (Aymara)
Length of the day on the summer solstice of the north
The following tables contain information on the length of the day on the summer solstice of the northern hemisphere and winter solstice of the southern hemisphere (i.e. June solstice). The data was collected from the website of the Finnish Meteorological Institute on 20 June 2016 as well as from certain other websites.
The data is arranged geographically and within the tables from the longest day to the shortest one.
See also
- Daytime
- Equinox
- Stonehenge
- Tekufah
- Xiazhi (Summer solstice in Chinese culture)
References
External links
- Table of dates/times from 1600-2400
Source of article : Wikipedia
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