Summer solstice

UT date and time of
equinoxes and solstices on Earth[1]
event equinox solstice equinox solstice
month March June September December
year
day timeday timeday timeday time
2010 2017:322111:282303:092123:38
2011 2023:212117:162309:042205:30
2012 2005:142023:092214:492111:12
2013 2011:022105:042220:442117:11
2014 2016:572110:512302:292123:03
2015 2022:452116:382308:202204:48
2016 2004:302022:342214:212110:44
2017 2010:282104:242220:022116:28
2018 2016:152110:072301:542122:23
2019 2021:582115:542307:502204:19
2020 2003:502021:442213:312110:02
Diagram of the Earth's seasons as seen from the north. Far left: summer solstice for the Northern Hemisphere. Front right: summer solstice for the Southern Hemisphere.

The summer solstice occurs when the tilt of a planet's semi-axis, in either the northern or the southern hemisphere, is most inclined toward the star (sun) that it orbits. Earth's maximum axial tilt toward the sun is 23° 26'. This happens twice each year, at which times the sun reaches its highest position in the sky as seen from the north or the south pole.

The summer solstice occurs during a hemisphere's summer. This is the northern solstice in the northern hemisphere and the southern 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[2][3] and between December 20 and December 23 each year in the southern hemisphere.[4]

When on a geographic pole, the sun reaches its greatest height, the moment of solstice, it can be noon only along that longitude which at that moment lies in the direction of the sun from the pole. For other longitudes, it is not noon. Noon has either passed or has yet to come. Hence the notion of a solstice day is useful. The term is colloquially used like midsummer to refer to the day on which solstice occurs. The summer solstice day has the longest period of daylight – except in the polar regions, where daylight is continuous, from a few days to six months around the summer solstice.

Worldwide, interpretation of the event 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.[5]

Solstice is derived from the Latin words sol (sun) and sistere (to stand still).

Celebrations

See also

References

  1. ↑ United States Naval Observatory (2010-06-10). "Earth's Seasons: Equinoxes, Solstices, Perihelion, and Aphelion, 2000-2020".
  2. ↑ "The June Solstice". Time and Date AS. Retrieved 2012-01-30.
  3. ↑ "Solstice (astronomy)". Britannica Online Encyclopedia. Retrieved 2011-06-20.
  4. ↑ "December Solstice". Time and Date AS. Retrieved 2012-01-30.
  5. ↑ "Summer solstice celebrations of Christianity, Judaism, Neopaganism, etc". Religioustolerance.org. Retrieved 2011-06-20.

External links