Darian calendar

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The Darian Calendar is a calendar design designed to meet the needs of future settlers on the planet Mars . It was created by space engineer and political scientist Thomas Gangale in 1985 and named after his son Darius.

Mars year and leap year calculation

The Martian solar day ( Sol ) and the Martian tropical year are the basic time periods that make up the Darian calendar. A sol is 39 minutes 35.244 seconds longer than the terrestrial solar day , and the tropical year on Mars is made up of 668.5907 sols. The basic formula for calculating the leap year assigns six years with 669 sols in length and four years with 668 sols in length to each Martian decade . The former are the leap years (even if in this case they are more common than the common years ) and are those years that are either odd or even divisible by 10.

Structure of the calendar

The year is divided into 24 months. The first 5 months of each quarter consist of 28 sols , whereas the sixth month only has 27 sols. The only exception to this is a leap year in which the last month of the year consists of 28 sols. The names of the months are derived from the names of the zodiac signs of the zodiac , with two months corresponding to one sign of the zodiac. The first of the two months bears the Latin name of the sign and the following one the name in Sanskrit . Sagittarius and Dhanus, the first two months, correspond to Sagittarius .

A week consists of seven sols, whereby it should be noted that the first week of the month always begins with the first day of the week. With a 27-solute month, this means that the last day of the fourth week is omitted.

In the table below, the days of the week are from left to right: Solis, Lunae, Martis, Mercurii, Jovis, Veneris, Saturni.

Sagittarius   Dhanus   Capricornus
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28
         
Makara   Aquarius   Kumbha
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27  
         
Pisces   Mina   Aries
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28
         
Mesha   Taurus   Rishabha
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27  
         
Gemini   Mithuna   Cancer
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28
         
Karka   Leo   Simha
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27  
         
Virgo   Kanya   Libra
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28
         
Tula   Scorpius   Vrishika
So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat So Lu Ma Me Yo Ve Sat
1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th 1 2 3 4th 5 6th 7th
8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th 8th 9 10 11 12 13 14th
15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st 15th 16 17th 18th 19th 20th 21st
22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28 22nd 23 24 25th 26th 27 28

The last day of the month of Vrishika is a leap day that does not occur every year.

Beginning of the year

The beginning of the Martian year is near the equinox , which marks the beginning of spring in the northern hemisphere of the planet. Mars currently has an inclination similar to that of the earth, so that the Martian seasons are perceptible. Due to the higher eccentricity of the Mars orbit compared to the Earth's orbit , however, there is a considerable increase in the seasons in one Martian hemisphere and, in turn, a weakening in the other Martian hemisphere. The most advanced calculations of the Daric Calendar take into account even a slight extension of the Martian Tropical Year over the course of several millennia . These force a more complicated leap year calculation (see the link below for more details).

epoch

The choice of the Martian era has been one of the greatest issues and controversies. Originally, July 1976 was planned for this, in recognition of the US Viking program with the first soft landing of a space probe on the surface of Mars. This choice created several problems. On the one hand, the celebration of the Viking landings was perceived by some groups of people as nationalistic , not least because the actual first soft landing of a Mars probe took place in 1971 by the Soviet Mars-3 probe , whose radio contact was broken after just twenty seconds. Furthermore, the many telescopic observations of Mars from the past 400 years had to be shifted to negative time data. Then in October 1999 Peter Kokh suggested the year 1609 or 1610 as the starting point, in recognition of the Kepler's laws developed by Johannes Kepler with the help of Tycho Brahe's observations and Galileo Galileo's first observations of Mars with the help of a telescope.

variants

Martiana

In 2002 Gangale developed a variant of the Daric calendar, which uses a repeating pattern to harmonize the months and the sols of the week . This will prevent skipping sols in certain weeks. In this variant of the calendar called Martiana , all months of a certain quarter begin on the same weekly sol, with the respective sol shifting from quarter to quarter at the beginning of the month.

The odd years are leap years with an additional day on the 28th Vrishika, so the even year starts again with the day Solis. An additional leap day, which occurs every 10 years with exceptions, remains outside the regular weekday counting, so the two-year cycle of the weekdays is retained.

The following table shows an extended formula for the leap years in different epochs:

Year range formula Average length of a calendar year
0000-2000 ( Y - 1) \ 2 + Y \ 10 - Y \ 100 + Y \ 1000 668.5910 sol
2001-4800 ( Y - 1) \ 2 + Y \ 10 - Y \ 150 668.5933 sol
4801-6800 ( Y - 1) \ 2 + Y \ 10 - Y \ 200 668.5950 sol
6801-8400 ( Y - 1) \ 2 + Y \ 10 - Y \ 300 668.5967 sol
08401-10000 ( Y - 1) \ 2 + Y \ 10 - Y \ 600 668.5983 sol

This extended switching rule results in an error of only one sol in 12,000 Martian years.

The following table shows the sol of the week with which each month of the corresponding quarter begins. The first quarter corresponds to spring in the Martian northern hemisphere and autumn in the Martian southern hemisphere .

  First quarter Second quarter Third quarter Fourth Quarter
Even years Solos Saturni Veneris Jovis
Odd years Mercurii Martis Lunae Solos

Further

Kim Stanley Robinson took up the idea of ​​the Daric calendar in his Martian trilogy. In contrast to the Daric calendar, not every sixth but every eighth month of this calendar is one with 27 sols, so there are only three of them. The months are also not named after the signs of the zodiac, but have the traditional names that count twice (January 1st, January 2nd, February 1st, February 2nd, etc.). Unlike Gangale, Robinson starts counting the year with the landing of the First Hundred in September 2027 . In total, this calendar is 669 Martian sols and 689 earthly days long. A similar calendar is described in the Manga Aqua by Kozue Amano . There, however, the months do not have names, but are simply counted according to current Japanese practice.

Other variants of the Darian calendar are the Darian Defrost Calendar and the Utopian Calendar . They differ from the actual Daric calendar through alternative month and weekday names. The Heron calendar also uses the Martina scheme and begins 13 days after the winter solstice in the northern hemisphere. He also uses the originally planned epoch, July 1975. The Naughton-O'Meara calendar , on the other hand, uses the usual epoch today, January 1st. It also strictly adheres to the corresponding year counting, which means that the year number changes changes once or twice during the Martian year.

Further Darian calendars

In 1998, Gangale adapted the Darian calendar for use on the four Galilean moons of Jupiter ( Io , Europa , Ganymed and Callisto ). In 2003 he developed a variant of the calendar for Titan .

Other Martian calendars

Another Martian calendar was developed in 1993 by Robert Zubrin . Like Thomas Gangale, Zubrin named the months after the zodiac signs of the zodiac . Unlike the Darish calendar, Zubrin's Mars calendar only has 12 months. Their length and name are determined by the sign of the zodiac in which Mars, as seen from the sun, is currently located. Zubrin set the beginning of the year on the spring equinox , and he chose the earthly year 1961 as the epoch , because on the one hand it is a year in which the beginning of the year on Earth and Mars fall on the same day. On the other hand, it is the last of these years before the first space probes landed there.

Another Martian calendar was proposed by David Powell in 1988. Like Zubrin's calendar, the Davidian Martian calendar also has 12 months, but they have the traditional names. The traditional seven-day week is maintained, said Tuesday , however, in Gaiatag renamed since Tuesday mutatis mutandis Martian means. The aim is to give the future Martian settlers as much familiar as possible. In an alternative version, however, a ten-day week ( decade ) is used, the days of which are named after the sun, the two moons of Mars and the seven other planets. The beginning of the Human Era ( 10,001 BC ), related to Mars, was used as the epoch so that all historical data are positive. It is switched in all years with an even year, unless they end in 00 , and in all odd years, which are divisible by 5 without a remainder. The leap day is inserted at the end of February or June. If a year ends with 0000, 2000, 4000, 5000, 6000, 8000 or 9000 , it begins with a millennium day , which is January 0 outside the weekly cycle. As with the Darian calendar, this calendar also has a variant for Jupiter.

Long before the calendars mentioned above were developed, Robert Grant Aitken had published a Martian calendar in 1936. The year is divided into four seasons , which in turn are divided into four quarters . The first three quarters always have 42 days, the last always 41 days. Thus a season has a total of 167 days. The last season is an exception. In leap years, the leap day is added to the last quarter of the year as the 42nd day, as is the case with the Darian calendar. Leap years are all years whose year is divisible by 2 without a remainder. If the year is also divisible by 10 without a remainder, a mid-year day is also added. This is added to the last quarter of the second season as the 42nd day. Leap years always start with a Wednesday, normal years start with a Sunday. The first season corresponds to spring in the northern hemisphere and autumn in the southern hemisphere. There is no defined epoch.

See also

Individual evidence

  1. The Martiana Calendar (English)
  2. ^ Thomas Gangale: The Architecture of Time, Part 2: The Darian System for Mars. Society of Automotive Engineers. SAE 2006-01-2249, July 1, 2006.
  3. Kim Stanley Robinson's Martian Calendar ( Memento of the original from September 11, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. in MangalaWiki (English)  @1@ 2Template: Webachiv / IABot / kimstanleyrobinson.info
  4. ^ Kozue Amano : Navigation 06: My First Customer . In: Aqua volume 2 . Tokyopop, February 2008, ISBN 978-1-4278-0313-9 , p. 7.
  5. Variants of the Daric Calendar (English)
  6. The calendar of Jupiter (English)
  7. The Daric Calendar for Titan (English)
  8. The Davidian Martian Calendar in the AKDave Wiki (English)
  9. Davidian Jupiter Calendar in the AKDave Wiki (English)
  10. ^ Robert S. Richardson: Exploring Mars . Kessinger Pub Co, ISBN 1-163-80805-9 (English).

literature

  • Thomas Gangale: Martian Standard Time. In: Journal of the British Interplanetary Society. Volume 39 (1986), No. 6, pp. 282-288.
    • ders .: Mare Chronium: A Brief History of Martian Time. In: American Astronautical Society. AAS 90-287, February 1, 1997.
    • ders .: The Darian Calendar. Mars Society . MAR 98-095. In: Robert M. Zubrin, Maggie Zubrin (Eds.): Proceedings of the Founding Convention of the Mars Society (August 13, 1998), Volume III. Univelt Inc., San Diego, California July 1, 1999.
    • ders .: The Architecture of Time, Part 2: The Darian System for Mars. Society of Automotive Engineers . SAE 2006-01-2249, July 1, 2006.
  • Thomas Gangale, Marilyn Dudley-Rowley: July 1, 2004. The Architecture of Time: Design Implications for Extended Space Missions. Society of Automotive Engineers. SAE Transactions: Journal of Aerospace, SAE 2004-01-2533, July 1, 2004.
    • This: Issues and Options for a Martian Calendar. In: Planetary and Space Science. Volume 53, December 1, 2005, pp. 1483-1495.
  • Thomas R. Meyer (Ed.): The Case for Mars IV: The International Exploration of Mars. Univelt Inc., San Diego, California.
  • Don Sakers: The Sf Book of Days. Speed-Of-C Productions, January 1, 2004, pp. 7, 19, 31, 53, 81, 103, 113, 123, 135, 145-149.
  • Arthur E. Smith: Mars: The next step. Taylor & Francis, Jan. 1, 1989, p. 7.
  • Robert S. Richardson: Exploring Mars . Kessinger Pub Co., ISBN 0-548-43843-9 or ISBN 978-1-104-84001-3 .

Web links

Other Martian calendars: