Planet symbols

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A planet symbol (or planetary symbol) is a graphical symbol used in astrology and astronomy to represent a classical planet (including the Sun and the Moon) or one of the modern planets. The symbols were also used in alchemy to represent the metals associated with the planets, and in calendars for their associated days. The use of these symbols derives from Classical Greco-Roman astronomy, though their current shapes are a development of the 16th century.

The classical planets, their symbols, days and most commonly associated planetary metals are:

planet Moon Mercury Venus Sun Mars Jupiter Saturn
symbol (text)
symbol (image) Moon decrescent symbol (fixed width).svg Mercury symbol (fixed width).svg Venus symbol (fixed width).svg Sun symbol (fixed width).svg Mars symbol (fixed width).svg Jupiter symbol (fixed width).svg Saturn symbol (fixed width).svg
day Monday Wednesday Friday Sunday Tuesday Thursday Saturday
metal silver mercury copper gold iron tin lead

The International Astronomical Union (IAU) discourages the use of these symbols in modern journal articles, and their style manual proposes one- and two-letter abbreviations for the names of the planets for cases where planetary symbols might be used, such as in the headings of tables.[1] The modern planets with their traditional symbols and IAU abbreviations are:

planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
symbol (text) 🜨
symbol (image) Mercury symbol (fixed width).svg Venus symbol (fixed width).svg Earth symbol (fixed width).svg Mars symbol (fixed width).svg Jupiter symbol (fixed width).svg Saturn symbol (fixed width).svg Uranus platinum symbol (fixed width).svg Neptune symbol (fixed width).svg
initial (IAU) Me[2] V E Ma J S U N

The symbols of Venus and Mars are also used to represent female and male in biology following a convention introduced by Carl Linnaeus in the 1750s.

History[edit]

Classical planets[edit]

The written symbols for Mercury, Venus, Jupiter, and Saturn have been traced to forms found in late Greek papyri.[3] Early forms are also found in medieval Byzantine codices which preserve ancient horoscopes.[4] Antecedents of the planetary symbols are attested in the attributes given to classical deities, represented in simplified pictographic form in the Roman era. Bianchini's planisphere (2nd century, Louvre inv. Ma 540)[5] shows the seven planets represented by portraits of the seven corresponding gods, each with a simple representation of an attribute, as follows: Mercury has a caduceus; Venus has a cord attached to her necklace which is connected to another necklace; Mars has a spear; Jupiter has a staff; Saturn has a scythe; the Sun has a circlet with rays emanating from it; and the Moon has a headdress with a crescent attached to it.[6]

A diagram in the astronomical compendium by Johannes Kamateros (12th century) shows the Sun represented by the circle with a ray, Jupiter by the letter zeta (the initial of Zeus, Jupiter's counterpart in Greek mythology), Mars by a shield crossed by a spear, and the remaining classical planets by symbols resembling the modern ones, though without the cross-marks seen in modern versions of Mercury, Venus and Saturn. These cross-marks first appear in the late 15th or early 16th century. According to Maunder, the addition of crosses appears to be "an attempt to give a savour of Christianity to the symbols of the old pagan gods."[6]

The modern symbols for the seven classical planets are found in a woodcut of the seven planets in a Latin translation of Abu Ma'shar's De Magnis Coniunctionibus printed at Venice in 1506, represented as the corresponding gods riding chariots.[7]

Earth symbol[edit]

Four-quarters-of-the-world symbol for Earth
Globus cruciger symbol for Earth

Earth is not one of the classical planets, as "planets" by definition were "wandering stars" as seen from Earth's surface. Earth's status as planet is a consequence of heliocentrism in the 16th century. Nonetheless, there is a pre-heliocentric symbol for the world, now used as a planetary symbol for the Earth. This is a circle crossed by a horizontal and vertical line, representing the world divided by fours rivers into the four quarters of the world (often translated as the four "corners" of the world): 🜨. A variant, now obsolete, had only the horizontal line: 🜔.[9]

A medieval European symbol for the world – the globus cruciger, ♁ (the globe surmounted by a Christian cross) – is also used as a planetary symbol; it resembles an inverted symbol for Venus.

The planetary symbols for Earth are encoded in Unicode at U+1F728 🜨 ALCHEMICAL SYMBOL FOR VERDIGRIS and U+2641 EARTH.

Classical planets[edit]

Moon[edit]

Decrescent symbol for the Moon
Encrescent symbol for the Moon

The crescent shape has been used to represent the Moon since earliest times. In classical antiquity, it is worn by lunar deities (Selene/Luna, Artemis/Diana, Men, etc.) either on the head or behind the shoulders, with its horns pointing upward. The representation of the moon as a simple crescent with the horns pointing to the side (as a heraldic crescent increscent or crescent decrescent) is attested from late Classical times.

The same symbol can be used in a different context not for the Moon itself but for a lunar phase, as part of a sequence of four symbols for "new moon" (U+1F311 🌑), "waxing" (U+263D ☽), "full moon" (U+1F315 🌕) and "waning" (U+263E ☾).

Mercury[edit]

The god Hermes (Mercury) with his caduceus
Crossed caduceus symbol for Mercury

The symbol ☿ for Mercury is a caduceus (a staff intertwined with two serpents), a symbol Mercury/Hermes throughout antiquity.[10] Some time after the 11th century, a cross was added to the bottom of the staff to make it seem more Christian.[3] Its Unicode codepoint is U+263F MERCURY.

Venus[edit]

Crossed copper (mirror?) symbol for Venus

The Venus symbol, ♀, consists of a circle with a small cross below it. It has been interpreted as standing for the mirror of the goddess, though that may not be its true origin; the planetary metal most commonly associated with Venus was copper, and polished copper has been used for mirrors from antiquity.[11] In the Bianchini's planisphere (2nd century), Venus is represented by a necklace.[5][failed verification] In the Greek Oxyrhynchus Papyri, the symbols for Venus and Mercury didn't have the cross on the bottom stroke,[3] and Venus appears without the cross (⚲) in Johannes Kamateros (12th century).

In botany and biology, the symbol for Venus is used to represent the female sex, alongside the symbol for Mars representing the male sex,[12] following a convention introduced by Linnaeus in the 1750s.[13] Arising from the biological convention, the symbol also came to be used in sociological contexts to represent women or femininity.

Unicode encodes the symbol as U+2640 FEMALE SIGN (♀), in the Miscellaneous Symbols block.[14]

Sun[edit]

Modern astronomical symbol for the Sun
Medieval astronomical symbol for the Sun[17]

The modern astronomical symbol for the Sun, the circumpunct (U+2609 SUN), was first used in the Renaissance. It possibly represents Apollo's golden shield with a boss; it is unknown if it traces descent from the nearly identical Egyptian hieroglyph for the Sun.

Bianchini's planisphere, produced in the 2nd century, shows a circlet with rays radiating from it.[6][5] In late Classical times, the Sun is attested as a circle with a single ray. A diagram in Johannes Kamateros' 12th century Compendium of Astrology shows the same symbol.[18] This older symbol is encoded by Unicode as U+1F71A 🜚 ALCHEMICAL SYMBOL FOR GOLD in the Alchemical Symbols block. Both symbols have been used alchemically for gold, as have more elaborate symbols showing a disk with multiple rays or even a face.

Mars[edit]

Spear and shield symbol for Mars

The Mars symbol, ♂, is a depiction of a circle with an arrow emerging from it, pointing at an angle to the upper right in Europe and to the upper left in India. As astrological symbol it represents the planet Mars. It is also the old and obsolete symbol for iron in alchemy. In zoology and botany, it is used to represent the male sex (alongside the astrological symbol for Venus representing the female sex),[12] following a convention introduced by Linnaeus in the 1750s.[13]

The symbol dates from at latest the 11th century, at which time it was an arrow across or through a circle, thought to represent the shield and spear of the god Mars; in the medieval form, for example in the 12th-century Compendium of Astrology by Johannes Kamateros, the spear is drawn across the shield.[18] The Greek Oxyrhynchus Papyri show a different symbol,[3] perhaps simply a spear.[5]

Its Unicode codepoint is U+2642 MALE SIGN (♂).

Jupiter[edit]

Zeus initial for Jupiter

The symbol for Jupiter, ♃, is originally a Greek zeta, Ζ, with a stroke indicating that it is an abbreviation (for Zeus, the Greek equivalent of Roman Jupiter).

Its Unicode codepoint is U+2643 JUPITER.

Saturn[edit]

Crossed kappa-rho ligature for Saturn

Salmasius and earlier attestations show that the symbol for Saturn, ♄, derives from the initial letters (Kappa, rho) of its ancient Greek name Κρόνος (Kronos), with a stroke to indicate an abbreviation.[13] By the time of Kamateros (12th century), the symbol had been reduced to a shape similar to a lower-case letter eta η, with the abbreviation stroke surviving (if at all) in the curl on the bottom-right end. The horizontal stroke was added along with the "Christianization" of other symbols in the early 16th century.

Its Unicode codepoint is U+2644 SATURN.

Modern discoveries[edit]

Uranus[edit]

Platinum symbol for Uranus
Herschel monogram for Uranus

The symbols for Uranus were created shortly after its discovery in 1781. One symbol, ⛢, invented by J. G. Köhler and refined by Bode, was intended to represent the newly discovered metal platinum; since platinum, commonly called white gold, was found by chemists mixed with iron, the symbol for platinum combines the alchemical symbols for iron, ♂, and gold, ☉.[19][20] Gold and iron are the planetary metals for the Sun and Mars, and so share their symbols. Several orientations were suggested, but an upright arrow is now universal.

Another symbol, ♅, was suggested by Lalande in 1784. In a letter to Herschel, Lalande described it as "un globe surmonté par la première lettre de votre nom" ("a globe surmounted by the first letter of your name").[21] The platinum symbol tends to be used by astronomers and the monogram by astrologers.

For use in computer systems, the symbols are encoded U+26E2 ASTRONOMICAL SYMBOL FOR URANUS and U+2645 URANUS.

Neptune[edit]

Trident symbol for Neptune
Le Verrier monogram for Neptune

Several symbols were proposed for Neptune to accompany the suggested names for the planet. Claiming the right to name his discovery, Urbain Le Verrier originally proposed the name the planet for the Roman God Neptune[22] and the symbol of a trident,[23] while falsely stating that this had been officially approved by the French Bureau des Longitudes.[22] In October, he sought to name the planet Leverrier, after himself, and he had loyal support in this from the observatory director, François Arago,[24] who in turn proposed a new symbol for the planet, ⯉ (proposed symbol for planet Leverrier).[25] However, this suggestion met with resistance outside France,[24] and French almanacs quickly reintroduced the name Herschel for Uranus, after that planet's discoverer Sir William Herschel, and Leverrier for the new planet,[26] though it was used by anglophone institutions.[27] Professor James Pillans of the University of Edinburgh defended the name Janus for the new planet, and proposed a key for its symbol.[23] Meanwhile, Struve presented the name Neptune on December 29, 1846, to the Saint Petersburg Academy of Sciences.[28] In August 1847, the Bureau des Longitudes announced its decision to follow prevailing astronomical practice and adopt the choice of Neptune, with Arago refraining from participating in this decision.[29] The planetary symbol was Neptune's trident, with the handle stylized either as a cross Neptune symbol (fixed width).svg, following Mercury, Venus and the asteroids, or as an orb Neptune orb symbol (fixed width).svg, following the symbols for Uranus and Earth.[9] The cross variant is the more common today.

For use in computer systems, the symbols are encoded as U+2646 NEPTUNE and U+2BC9 NEPTUNE FORM TWO.

Pluto[edit]

Bident symbol for Pluto
Percival Lowell monogram for Pluto

Pluto was almost universally considered a planet from its discovery in 1930 until its re-classification as a dwarf planet (planetoid) by the IAU in 2006. Planetary geologists and astrologers continue to treat it as a planet.[citation needed] The original planetary symbol for Pluto was a monogram of the letters P and L. Astrologers generally use a bident with an orb. NASA has used the bident symbol since Pluto's reclassification. These symbols are encoded as U+2647 PLUTO and U+2BD3 PLUTO FORM TWO.

Minor planets[edit]

"Designation of celestial bodies" in a German almanac printed 1850[30]

In the 19th century, planetary symbols for the major asteroids were also in use, including 1 Ceres (a reaper's sickle, encoded U+26B3 CERES), 2 Pallas (a lance, U+26B4 PALLAS) and 3 Juno (a sceptre, encoded U+26B5 JUNO). Encke (1850) proposed symbols for 5 Astraea, 6 Hebe, 7 Iris, 8 Flora and 9 Metis.[30]

In the late 20th century, astrologers abbreviated the symbol for 4 Vesta (the sacred fire of Vesta, encoded U+26B6 VESTA), and introduced symbols for 10 Hygiea (a caduceus – a common error in the USA for a staff of Asclepius, itself an error for the snake symbol of Hygiea – encoded U+2BDA HYGIEA) and for 2060 Chiron, discovered in 1977 (a key, U+26B7 CHIRON). Chiron's symbol was adapted as additional centaurs were discovered; symbols for 5145 Pholus and 7066 Nessus have been encoded in Unicode. The abbreviation of the Vesta symbol is now universal, and the astrological symbol for Pluto has been used astronomically for Pluto as a dwarf planet.

In the early 21st century, symbols for the trans-Neptunian dwarf planets have come into use, particularly Eris (the hand of Eris, ⯰, but also ⯱), Sedna, Haumea, Makemake, Gonggong, Quaoar and Orcus. The symbols for Eris and Sedna are currently in Unicode, and those for the others have been accepted for the version 15 (2022).

Unicode symbol
Ceres Ceres symbol (fixed width).svg (⚳) CERES at U+26B3.[31]
Pallas Pallas symbol (fixed width).svg (⚴) PALLAS at U+26B4.[31]
Juno Juno symbol (fixed width).svg (⚵) JUNO at U+26B5.[31]
Vesta Vesta symbol (fixed width).svg (⚶) VESTA at U+26B6.[31]
Chiron Chiron symbol (fixed width).svg (⚷) CHIRON at U+26B7.[31]
Pholus Pholus symbol.svg (⯛) PHOLUS at U+2BDB
Nessus Nessus symbol.svg (⯛) NESSUS at U+2BDC
Orcus Orcus symbol (fixed width).svg (🝿) ORCUS scheduled for U+1F77F
Haumea Haumea symbol (fixed width).svg (🝻) HAUMEA scheduled for U+1F77B
Quaoar Quaoar symbol (fixed width).svg (🝾) QUAOAR scheduled for U+1F77E
Makemake Makemake symbol (fixed width).svg (🝼) MAKEMAKE scheduled for U+1F77C
Gonggong Gonggong symbol (fixed width).svg (🝽) GONGGONG scheduled for U+1F77D
Eris Eris symbol (fixed width).svg (⯰) ERIS FORM ONE at U+2BF0
Eris arrow symbol (fixed width).svg (⯱) ERIS FORM TWO at U+2BF1
Sedna Sedna symbol (fixed width).svg (⯲) SEDNA at U+2BF2

See also[edit]

References[edit]

  1. ^ The IAU Style Manual (PDF). 1989. p. 27.
  2. ^ Or 'H', with 'M' for 'Mars'. In a provision for the unlikely event a satellite were ever discovered around Mercury, it would be abbreviated 'H1'.
  3. ^ a b c d e f g h i j k Jones, Alexander (1999). Astronomical papyri from Oxyrhynchus. pp. 62–63. ISBN 0-87169-233-3. It is now possible to trace the medieval symbols for at least four of the five planets to forms that occur in some of the latest papyrus horoscopes ([ P.Oxy. ] 4272, 4274, 4275 [...]). Mercury's is a stylized caduceus. … The ideal form of Mars' symbol is uncertain, and perhaps not related to the later circle with an arrow through it.
  4. ^ Neugebauer, Otto (1975). A history of ancient mathematical astronomy. pp. 788–789. ISBN 0-387-06995-X.
  5. ^ a b c d "Bianchini's planisphere". Florence, Italy: Istituto e Museo di Storia della Scienza (Institute and Museum of the History of Science). Retrieved 2010-03-17.
  6. ^ a b c Maunder (1934)
  7. ^ Maunder (1934:239)
  8. ^ BNF Arabe 2583 fol. 15v. Saturn is shown as a black bearded man, kneeling and holding a scythe or axe; Mercury is shown as a scribe holding an open codex; Jupiter as a man of the law wearing a turban; Venus as a lute-player; Mars as a helmeted warrior holding a sword and the head of an enemy.
  9. ^ a b "Solar System", in The English Cyclopaedia of Arts and Sciences, vol. VII-VIII, 1861
  10. ^ Cox, Arthur (2001). Allen's astrophysical quantities. Springer. p. 2. ISBN 0-387-95189-X.
  11. ^ Stearn, William T. (May 1968). "The Origin of the Male and Female Symbols of Biology". Taxon. 11 (4): 109–113. doi:10.2307/1217734. JSTOR 1217734. S2CID 87030547.
  12. ^ a b Schott, GD (December 2005). "Sex symbols ancient and modern: their origins and iconography on the pedigree". The BMJ. 331 (7531): 1509–10. doi:10.1136/bmj.331.7531.1509. ISSN 0959-8138. PMC 1322246. PMID 16373733.
  13. ^ a b c Stearn, William T. (May 1962). "The Origin of the Male and Female Symbols of Biology" (PDF). Taxon. 11 (4): 109–113. doi:10.2307/1217734. ISSN 0040-0262. JSTOR 1217734. In his Systema Naturae (Leyden, 1735) he [Linnaeus] used them with their traditional associations for metals. Their first biological use is in the Linnaean dissertation Plantae hybridae xxx sistit J. J. Haartman (1751) where in discussing hybrid plants Linnaeus denoted the supposed female parent species by the sign ♀, the male parent by the sign ♂, the hybrid by ☿: 'matrem signo ♀, patrem ♂ & plantam hybridam ☿ designavero'. In subsequent publications he retained the signs ♀ and ♂ for male and female individuals but discarded ☿ for hybrids; the last are now indicated by the multiplication sign ×. Linnaeus's first general use of the signs of ♀ and ♂ was in his Species Plantarum (1753) written between 1746 and 1752 and surveying concisely the whole plant kingdom as then known. ... In order to save space Linnaeus employed the astronomical symbols of Saturn, Jupiter, Mars and the Sun to denote woody, hebaceous perennial, biennial and annual plants respectively [ed.: the orbital periods of Saturn, Jupiter, Mars and Earth about the Sun are 29, 12, 2 and 1 year] ... and Mercury, Mars and Venus for the hermaphrodite, male and female conditions ... Later, in his Mantissa Plantarum (1767) and Mantissa Plantarum altera (1771), Linnaeus regularly used ♂, ♀ and ☿ for male, female and hermaphrodite flowers respectively. Their aptness made them easy to remember and their convenience led to their general acceptance in zoology as well as botany. Koelreuter found them especially convenient when recording his experiments in hybridization; as late as 1778 he used the sign ☿ to denote a hybrid plant.
  14. ^ In the official code chart glossed " = Venus = alchemical symbol for copper → 1F469 👩 woman → 1F6BA 🚺 womens symbol".
  15. ^ Falun was the site of a copper mine from at least the 13th century. A coat of arms including a copper sign is recorded for 1642; the current design dates to the early 20th century, and was given official recognition in 1932. It was slightly simplified upon the formation of the modern municipality in 1971 (registered with the Swedish Patent and Registration Office. in 1988).
  16. ^ Attributed to Robin Morgan in the 1960s. "Morgan designed the universal logo of the women's movement, the woman's symbol centered with a raised fist" (robinmorgan.net)
  17. ^ Maunder, A.S.D. (1934). "The origin of the symbols of the planets". The Observatory. Vol. 57. pp. 238–247. Bibcode:1934Obs....57..238M.
  18. ^ a b Neugebauer, Otto; Van Hoesen, H. B. (1987). Greek Horoscopes. pp. 1, 159, 163.
  19. ^ a b Bode, J.E. (1784). Von dem neu entdeckten Planeten. Beim Verfaszer. pp. 95–96. Bibcode:1784vdne.book.....B.
  20. ^ Gould, B.A. (1850). Report on the history of the discovery of Neptune. Smithsonian Institution. p. 5.
  21. ^ Francisca Herschel (August 1917). "The meaning of the symbol H+o for the planet Uranus". The Observatory. 40: 306. Bibcode:1917Obs....40..306H.
  22. ^ a b Littmann, Mark; Standish, E. M. (2004). Planets Beyond: Discovering the Outer Solar System. Courier Dover Publications. p. 50. ISBN 0-486-43602-0.
  23. ^ a b Pillans, James (1847). "Ueber den Namen des neuen Planeten". Astronomische Nachrichten. 25 (26): 389–392. Bibcode:1847AN.....25..389.. doi:10.1002/asna.18470252602.
  24. ^ a b Baum, Richard; Sheehan, William (2003). In Search of Planet Vulcan: The Ghost in Newton's Clockwork Universe. Basic Books. pp. 109–110. ISBN 0-7382-0889-2.
  25. ^ Schumacher, H. C. (1846). "Name des Neuen Planeten". Astronomische Nachrichten. 25: 81–82. Bibcode:1846AN.....25...81L. doi:10.1002/asna.18470250603.
  26. ^ Gingerich, Owen (October 1958). "The Naming of Uranus and Neptune". Astronomical Society of the Pacific Leaflets. 8 (352): 9–15. Bibcode:1958ASPL....8....9G.
  27. ^ E.g. Proceedings of the American Academy of Arts and Sciences, vol. 1, p. 287 ff, 334 ff, 1848
  28. ^ Hind, J. R. (1847). "Second report of proceedings in the Cambridge Observatory relating to the new Planet (Neptune)". Astronomische Nachrichten. 25 (21): 309–314. Bibcode:1847AN.....25..309.. doi:10.1002/asna.18470252102.
  29. ^ Bureau Des Longitudes, France (1847). Connaissance des temps: ou des mouvementes célestes, à l'usage des astronomes. p. unnumbered front matter.
  30. ^ a b Johann Franz Encke, Berliner Astronomisches Jahrbuch für 1853, Berlin 1850, p. VIII
  31. ^ a b c d e In the official code chart.

Sources[edit]

  • Maunder, A. S. D. (1934). "The origin of the symbols of the planets". The Observatory. 57: 238–247. Bibcode:1934Obs....57..238M.