March equinox

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UT date and time of
equinoxes and solstices on Earth [1] [2]
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monthMarch [3] June [4] September [5] December [6]
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20192021:582115:542307:502204:19
20202003:502021:432213:312110:03
20212009:372103:322219:212115:59
20222015:332109:142301:042121:48
20232021:252114:582306:502203:28
20242003:072020:512212:442109:20
20252009:022102:422218:202115:03
20262014:462108:252300:062120:50
20272020:252114:112306:022202:43
20282002:172020:022211:452108:20
20292008:012101:482217:372114:14
Illumination of Earth by the Sun on the day of an equinox Earth-lighting-equinox EN.png
Illumination of Earth by the Sun on the day of an equinox

The March equinox [7] [8] or northward equinox [9] is the equinox on the Earth when the subsolar point appears to leave the Southern Hemisphere and cross the celestial equator, heading northward as seen from Earth. The March equinox is known as the vernal equinox (spring equinox) in the Northern Hemisphere and as the autumnal equinox (autumn equinox or fall equinox) in the Southern Hemisphere. [8] [7] [10]

Contents

On the Gregorian calendar, the northward equinox can occur as early as 19 March or as late as 21 March at 0° longitude. For a common year the computed time slippage is about 5 hours 49 minutes later than the previous year, and for a leap year about 18 hours 11 minutes earlier than the previous year. Balancing the increases of the common years against the losses of the leap years keeps the calendar date of the March equinox from drifting more than one day from 20 March each year.

The March equinox may be taken to mark the beginning of astronomical spring and the end of astronomical winter in the Northern Hemisphere but marks the beginning of astronomical autumn and the end of astronomical summer in the Southern Hemisphere. [11]

In astronomy, the March equinox is the zero point of sidereal time and, consequently, the right ascension and ecliptic longitude. [12] It also serves as a reference for calendars and celebrations in many cultures and religions.

Constellation

The point where the Sun crosses the celestial equator northwards is called the First Point of Aries. However, due to the precession of the equinoxes, this point is no longer in the constellation Aries, but rather in Pisces. [13] By the year 2600 it will be in Aquarius. The Earth's axis causes the First Point of Aries to travel westwards across the sky at a rate of roughly one degree every 72 years. Based on the modern constellation boundaries, the northward equinox passed from Taurus into Aries in the year −1865 (1866 BC), passed into Pisces in the year −67 (68 BC), will pass into Aquarius in the year 2597, and will pass into Capricornus in the year 4312. It passed by (but not into) a 'corner' of Cetus at 0°10′ distance in the year 1489.[ citation needed ]

Apparent movement of the Sun

In its apparent motion on the day of an equinox, the Sun's disk crosses the Earth's horizon directly to the east at sunrise; and again, some 12 hours later, directly to the west at sunset. The March equinox, like all equinoxes, is characterized by having an almost exactly equal amount of daylight and night across most latitudes on Earth. [14]

Culture

Calendars

The Babylonian calendar began with the first new moon after the March equinox, the day after the return of the Sumerian goddess Inanna (later known as Ishtar) from the underworld, in the Akitu ceremony, with parades through the Ishtar Gate to the Eanna temple and the ritual re-enactment of the marriage to Tammuz, or Sumerian Dummuzi.[ citation needed ]

The Persian calendar begins each year at the northward equinox, observationally determined at Tehran. [15]

The Indian national calendar starts the year on the day next to the vernal equinox on 22 March (21 March in leap years) with a 30-day month (31 days in leap years), then has 5 months of 31 days followed by 6 months of 30 days. [15]

Julian calendar

The Julian calendar reform lengthened seven months and replaced the intercalary month with an intercalary day to be added every four years to February. It was based on a length for the year of 365 days and 6 hours (365.25 d), while the mean tropical year is about 11 minutes and 15 seconds less than that. This had the effect of adding about three quarters of an hour every four years. The effect accumulated from inception in 45 BC until the 16th century, when the northern vernal equinox fell on 10 or 11 March. [16]

The date in 1452 was 11 March, 11:52 (Julian). [17] In 2547 it will be 20 March, 21:18 (Gregorian) and 3 March, 21:18 (Julian). [18]

Commemorations

Bas-relief in Persepolis, a symbol of Iranian Nowruz: a bull (symbolizing the Earth) and lion (the Sun) in eternal combat are equal in power on the equinox. Nowruz Zoroastrian.jpg
Bas-relief in Persepolis, a symbol of Iranian Nowruz: a bull (symbolizing the Earth) and lion (the Sun) in eternal combat are equal in power on the equinox.
Chichen Itza during the spring equinox--Kukulkan, the famous descent of the snake ChichenItzaEquinox.jpg
Chichen Itza during the spring equinox—Kukulkan, the famous descent of the snake

Abrahamic tradition

  • The Jewish Passover usually falls on the first full moon after the Northern Hemisphere vernal equinox, [19] although occasionally (currently three times every 19 years[ citation needed ]) it will occur on the second full moon. [20]
  • The Christian Churches calculate Easter as the first Sunday after the first full moon on or after the March equinox. The official church definition for the equinox is 21 March. The Eastern Orthodox Churches use the older Julian calendar, while the western churches use the Gregorian calendar, and the western full moons currently fall four, five or 34 days before the eastern ones. The result is that the two Easters generally fall on different days but they sometimes coincide. The earliest possible western Easter date in any year is 22 March on each calendar. The latest possible western Easter date in any year is 25 April. [21]

Iranian tradition

  • The northward equinox marks the first day of various calendars including the Iranian calendar. The ancient Iranian peoples' new year's festival of Nowruz can be celebrated 20 March or 21 March. According to the ancient Persian mythology Jamshid, the mythological king of Persia, ascended to the throne on this day and each year this is commemorated with festivities for two weeks. Along with Iranian peoples, it is also a holiday celebrated by Turkic people, the North Caucasus and in Albania. It is also a holiday for Zoroastrians, adherents of the Baháʼí Faith and Nizari Ismaili Muslims irrespective of ethnicity. [22]

West Asia and North Africa

South and Southeast Asia

According to the sidereal solar calendar, celebrations which originally coincided with the March equinox now take place throughout South Asia and parts of Southeast Asia on the day when the Sun enters the sidereal Aries, generally around 14 April.

East Asia

  • The traditional East Asian calendars divide a year into 24 solar terms (节气, literally "climatic segments"), and the vernal equinox ( Chūnfēn , Chinese and Japanese : 春分; Korean : 춘분; Vietnamese : Xuân phân) marks the middle of the spring. In this context, the Chinese character 分 means "(equal) division" (within a season).
  • In Japan, Vernal Equinox Day (春分の日 Shunbun no hi) is an official national holiday, and is spent visiting family graves and holding family reunions. [23] [24] Higan (お彼岸) is a Buddhist holiday exclusively celebrated by Japanese sects during both the Spring and Autumnal Equinox. [23]

Europe

Equinox at the site of Pizzo Vento, Fondachelli Fantina, Sicily Equinozio da Pizzo Vento,tramonto fondachelli fantina, sicilia.JPG
Equinox at the site of Pizzo Vento, Fondachelli Fantina, Sicily

The Americas

Modern culture

See also

Related Research Articles

A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and set "due west". This occurs twice each year, around 20 March and 23 September.

The Revised Julian calendar, or less formally the new calendar and also known as the Milanković calendar, is a calendar proposed in 1923 by the Serbian scientist Milutin Milanković as a more accurate alternative to both Julian and Gregorian calendars. At the time, the Julian calendar was still in use by all of the Eastern Orthodox Church and affiliated nations, while the Catholic and Protestant nations were using the Gregorian calendar. Thus, Milanković's aim was to discontinue the divergence between the naming of dates in Eastern and Western churches and nations. It was intended to replace the Julian calendar in Eastern Orthodox Churches and nations. From 1 March 1600 through 28 February 2800, the Revised Julian calendar aligns its dates with the Gregorian calendar, which had been proclaimed in 1582 by Pope Gregory XIII.

Reform of the date of Easter refers to proposals to change the date for the annual celebration of Easter. These proposals include setting a fixed date or agreeing between Eastern and Western Christendom a common basis for calculating the date of Easter so that all Christians celebrate the Festival on the same day. As of 2023, no such agreement has been reached.

A solstice is the time when the Sun reaches its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around 20-22 June and 20-22 December. In many countries, the seasons of the year are defined by reference to the solstices and the equinoxes.

<span class="mw-page-title-main">Year</span> Time of one planets orbit around a star

A year is the time taken for astronomical objects to complete one orbit. For example, a year on Earth is the time taken for Earth to revolve around the Sun. Generally, a year is taken to mean a calendar year, but the word is also used for periods loosely associated with the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. The term can also be used in reference to any long period or cycle, such as the Great Year.

<span class="mw-page-title-main">Zodiac</span> Area of the sky divided into twelve signs

The zodiac is a belt-shaped region of the sky that extends approximately 8° north and south of the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year. Also within this zodiac belt appear the Moon and the brightest planets, along their orbital planes. The zodiac is divided along the ecliptic into 12 equal parts ("signs"), each occupying 30° of celestial longitude. These signs roughly correspond to the astronomical constellations with the following modern names: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces.

A solar calendar is a calendar whose dates indicate the season or almost equivalently the apparent position of the Sun relative to the stars. The Gregorian calendar, widely accepted as a standard in the world, is an example of a solar calendar. The main other types of calendar are lunar calendar and lunisolar calendar, whose months correspond to cycles of Moon phases. The months of the Gregorian calendar do not correspond to cycles of the Moon phase.

<span class="mw-page-title-main">Date of Easter</span>

As a moveable feast, the date of Easter is determined in each year through a calculation known as computus. Easter is celebrated on the first Sunday after the Paschal full moon. Determining this date in advance requires a correlation between the lunar months and the solar year, while also accounting for the month, date, and weekday of the Julian or Gregorian calendar. The complexity of the algorithm arises because of the desire to associate the date of Easter with the date of the Jewish feast of Passover which, Christians believe, is when Jesus was crucified.

<span class="mw-page-title-main">Swedish calendar</span> Calendar in use in Sweden from 1700 to 1712

The Swedish calendar or Swedish style was a calendar in use in Sweden and its possessions from 1 March 1700 until 30 February 1712. It was one day ahead of the Julian calendar and ten days behind the Gregorian calendar. Easter was calculated astronomically, with a minor exception, from 1740 to 1844.

<span class="mw-page-title-main">Spring (season)</span> One of the Earths four temperate seasons

Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses until the Summer Solstice in June and December.

<span class="mw-page-title-main">September equinox</span> When sun appears directly over equator

The September equinox is the moment when the Sun appears to cross the celestial equator, heading southward. Because of differences between the calendar year and the tropical year, the September equinox may occur from September 21 to 24.

<span class="mw-page-title-main">Timekeeping on Mars</span> Proposed approaches to tracking date and time on the planet Mars

Though no standard exists, numerous calendars and other timekeeping approaches have been proposed for the planet Mars. The most commonly seen in the scientific literature denotes the time of year as the number of degrees on its orbit from the northward equinox, and increasingly there is use of numbering the Martian years beginning at the equinox that occurred April 11, 1955.

The term Uttarāyaṇa is derived from two different Sanskrit words – "uttaram" (North) and "ayanam" (movement) – thus indicating the northward movement of the Sun. In the Gregorian calendar, this pertains to the "actual movement of the sun with respect to the earth." Also known as the six month period that occurs between the winter solstice and summer solstice. According to the Indian solar calendar, it refers to the movement of the Sun through the zodiac. This difference is because the solstices continually precess at a rate of 50 arcseconds per year due to the precession of the equinoxes, i.e. this difference is the difference between the sidereal and tropical zodiacs. The Surya Siddhanta bridges this difference by juxtaposing the four solstitial and equinoctial points with four of the twelve boundaries of the rashis.

The Gregorian calendar is the calendar used in most parts of the world. It went into effect in October 1582 following the papal bull Inter gravissimas issued by Pope Gregory XIII, which introduced it as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years differently so as to make the average calendar year 365.2425 days long, more closely approximating the 365.2422-day 'tropical' or 'solar' year that is determined by the Earth's revolution around the Sun.

A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's tilted orbit around the Sun. In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to undergo hibernation or to migrate, and plants to be dormant. Various cultures define the number and nature of seasons based on regional variations, and as such there are a number of both modern and historical definitions of the seasons.

<span class="mw-page-title-main">Gnomon of Saint-Sulpice</span> Astronomical Measurement Device

The Gnomon of Saint-Sulpice is an astronomical measurement device located in the Church of Saint-Sulpice in Paris, France. It is a gnomon, a device designed to cast a shadow on the ground in order to determine the position of the sun in the sky. In early modern times, other gnomons were also built in several Italian and French churches in order to better calculate astronomical events. Those churches are Santa Maria del Fiore in Florence, San Petronio in Bologna, and the Church of the Certosa in Rome. These gnomons ultimately fell into disuse with the advent of powerful telescopes.

A tropical year or solar year is the time that the Sun takes to return to the same position in the sky – as viewed from the Earth or another celestial body of the Solar System – thus completing a full cycle of astronomical seasons. For example, it is the time from vernal equinox to the next vernal equinox, or from summer solstice to the next summer solstice. It is the type of year used by tropical solar calendars.

<span class="mw-page-title-main">Astronomical basis of the Hindu calendar</span> Applied astronomy of ancient India

The Hindu calendar is based on a geocentric model of the Solar System. A geocentric model describes the Solar System as seen by an observer on the surface of the Earth.

<span class="mw-page-title-main">Solar New Year</span> Beginning of solar calendar year

The Solar New Year is the beginning of the solar calendar year. This event is observed at different times of year and with varying practices in cultures across the globe. The most common bases chosen to begin a new calendar year are the winter solstice, summer solstice, the spring equinox and the autumnal equinox. South and South-east Asian solar calendars are more formally linked to astronomical events.

References

  1. ↑ Astronomical Applications Department of USNO. "Earth's Seasons - Equinoxes, Solstices, Perihelion, and Aphelion" . Retrieved 1 August 2022.
  2. ↑ "Solstices and Equinoxes: 2001 to 2100". AstroPixels.com. 20 February 2018. Retrieved 21 December 2018.
  3. ↑ Équinoxe de printemps entre 1583 et 2999
  4. ↑ Solstice d’été de 1583 à 2999
  5. ↑ Équinoxe d’automne de 1583 à 2999
  6. ↑ Solstice d’hiver
  7. 1 2 Serway, Raymond; Jewett, John (8 January 2013). Physics for Scientists and Engineers. Cengage Learning. p. 409. ISBN   978-1-285-53187-8.
  8. 1 2 United States Naval Training Command (1972). Navigation compendium. U.S. Govt. Print. Off. p. 88.
  9. ↑ "Embracing the Equinox". Night Sky Network. Jet Propulsion Laboratory. 18 February 2022. Retrieved 19 July 2022.
  10. ↑ Desonie, Dana (2008). Polar Regions: Human Impacts. Infobase Publishing. p. 6. ISBN   978-1-4381-0569-7.
  11. ↑ "Defining Seasons". timeanddate.com.
  12. ↑ Zeilik, M.; Gregory, S. A. (1998). Introductory Astronomy & Astrophysics (4th ed.). Saunders College Publishing. p. 36. ISBN   0030062284.
  13. ↑ Spherical Astronomy. Krishna Prakashan Media. pp. 233ff. GGKEY:RDRHQ35FBX7.
  14. ↑ Resnick, Brian (19 March 2020). "The spring equinox is Thursday: 8 things to know about the first day of spring". Vox. Retrieved 20 March 2020.
  15. 1 2 Bromberg, Irv. "The Lengths of the Seasons". University of Toronto, Canada. Retrieved 6 July 2013.
  16. ↑ Blackburn, Bonnie; Holford-Strevens, Leofranc (2003). The Oxford companion to the Year: An exploration of calendar customs and time-reckoning . Oxford University Press. p.  683. ISBN   0-19-214231-3. Corrected reprinting of original 1999 edition.
  17. ↑ Smith, Ivan (10 May 2002). "Vernal Equinox, 1452–1811". Ns1763.ca. Retrieved 6 July 2013.
  18. ↑ Smith, Ivan (10 May 2002). "Vernal Equinox, 2188–2547". Ns1763.ca. Retrieved 6 July 2013.
  19. ↑ Burnaby, Sherrard Beaumont (1901). "Elements of the Jewish and Muhammedan calendars with rules and tables and explanatory notes on the Julian and Gregorian calendars". London. pp. 13–14.
  20. ↑ Burnaby, Sherrard Beaumont (1901). "Elements of the Jewish and Muhammedan calendars with rules and tables and explanatory notes on the Julian and Gregorian calendars". London. pp. 9–10.
  21. ↑ Cooley, Keith (2001). "Keith's Moon Facts". Hiwaay.net personal pages.[ self-published source ]
  22. ↑ "Navroz". The Ismaili. Islamic Publications Limited. Retrieved 4 July 2011.
  23. 1 2 Milton Walter Meyer (1993). Japan: A Concise History . Rowman & Littlefield. pp.  246. ISBN   978-0-8226-3018-0.
  24. ↑ Yoneyuki Sugita (18 August 2016). Social Commentary on State and Society in Modern Japan. Springer. p. 23. ISBN   978-981-10-2395-8.
  25. ↑ "Disablót". Nationalencyklopedin (in Swedish).
  26. ↑ "Visitors Guide to the Woodhenge". 8 January 2019. Retrieved 21 December 2019.
  27. ↑ Iseminger, William. "Welcome the Fall Equinox at Cahokia Mounds". Illinois Department of Natural Resources. Retrieved 20 December 2017.
  28. ↑ "Winter Solstice Sunrise Observance at Cahokia Mounds". Collinsville Chamber of Commerce. Retrieved 20 December 2017.
  29. ↑ "Cahokia Mounds Mark Spring Equinox : The keepers of Cahokia Mounds will host a spring gathering to celebrate the vernal equinox". Indian Country Today. Indian Country Media Network . Retrieved 20 December 2017.
  30. ↑ "World Citizens Day—World Unity Day". Consultative Assembly of the Peoples Congress. 2007.
  31. ↑ "With Spring comes the Baháʼí New Year". National Spiritual Assembly of the Baháʼís of the United States. Archived from the original on 28 September 2011. Retrieved 4 July 2011.
  32. ↑ Wyatt, Kristen. "Annapolis Welcomes Spring by Burning Socks". Associated Press . Annapolis, Maryland. Retrieved 15 February 2022.
  33. ↑ Rey, Diane. "Hillsmere Joins in Sock Burning Tradition". The Capital . Annapolis, Maryland. Retrieved 25 April 2011.
  34. ↑ Gander, Kashmira (20 March 2014). "Spring equinox 2014: First day of spring marked by Google Doodle". The Independent. London. Retrieved 20 March 2014.
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