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:
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. The modern planets with their traditional symbols and IAU abbreviations are:
The written symbols for Mercury, Venus, Jupiter, and Saturn have been traced to forms found in late Greek papyri. Early forms are also found in medieval Byzantine codices which preserve ancient horoscopes. 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) 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.
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."
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.
Early modern depiction of the planet symbols in an alchemical context (Musaeum Hermeticum, 1678)
Depiction of the planets in a 15th-century Arabic manuscript of Abu Ma'shar's "Book of nativities"
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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: .
The planetary symbols for Earth are encoded in Unicode at U+1F728 🜨 ALCHEMICAL SYMBOL FOR VERDIGRIS and U+2641 ♁ EARTH.
The Olympian gods, atop the world
Stylized Earth symbol
A simple globus cruciger
In this globus cruciger, the cross is surmounted on a globe that resembles the sun-cross symbol
In this globus cruciger, the cross is surmounted on a celestial orb with stars
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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 ☾).
The symbol for the Moon in a medieval Byzantine (11th c.) ms. The appearance in late Classical times was similar.
Stylized Moon symbol
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The symbol ☿ for Mercury is a caduceus (a staff intertwined with two serpents), a symbol Mercury/Hermes throughout antiquity. Some time after the 11th century, a cross was added to the bottom of the staff to make it seem more Christian.
Its Unicode codepoint is U+263F ☿ MERCURY (HTML
The symbol for Mercury in late Classical (4th c.) and medieval Byzantine (11th c.) mss
Stylized Mercury symbol
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. In the Bianchini's planisphere (2nd century), Venus is represented by a necklace.[failed verification] In the Greek Oxyrhynchus Papyri, the symbols for Venus and Mercury didn't have the cross on the bottom stroke, 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, following a convention introduced by Linnaeus in the 1750s. Arising from the biological convention, the symbol also came to be used in sociological contexts to represent women or femininity.
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A bronze mirror, of the type associated with Venus
The symbol for Venus in late Classical (4th c.) and medieval Byzantine (11th c.) mss
Stylized Venus symbol
Double-Venus symbol on a lesbian pride flag
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The modern astronomical symbol for the Sun, the circumpunct (U+2609 ☉ SUN (HTML
☉)), 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.
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. This older symbol is encoded by Unicode as U+1F71A 🜚 ALCHEMICAL SYMBOL FOR GOLD (HTML
🜚) 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.
The disk with a ray as a symbol for the Sun in late Classical (4th c.) and medieval Byzantine (11th c.) mss
Stylized circumpunct symbol for the Sun
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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), following a convention introduced by Linnaeus in the 1750s.
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. The Greek Oxyrhynchus Papyri show a different symbol, perhaps simply a spear.
3rd-century coin with Mars on the reverse, with lance and shield. The same symbols were used for Athena (Pallas).
The symbol for Mars in late Classical (6th c.) and medieval Byzantine (11th c.) mss.
The Mars symbol in the municipal coat of arms of Loppi in Finland
Double-Mars symbol on a gay-pride flag
Stylized Mars symbol
Its Unicode codepoint is U+2642 ♂ MALE SIGN (HTML
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Its Unicode codepoint is U+2643 ♃ JUPITER (HTML
The symbol for Jupiter in late Classical (4th c.) and medieval Byzantine (11th c.) mss
Stylized Jupiter symbol
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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. 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 (HTML
Stylized Saturn symbol
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, ☉. 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"). 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.
The planetary symbols as rendered in 1784, including the newly discovered Uranus (left)
Stylized Uranus monogram
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 and the symbol of a trident, while falsely stating that this had been officially approved by the French Bureau des Longitudes. In October, he sought to name the planet Leverrier, after himself, and he had loyal support in this from the observatory director, François Arago, who in turn proposed a new symbol for the planet, ⯉ (). However, this suggestion met with resistance outside France, French almanacs quickly reintroduced the name Herschel for Uranus, after that planet's discoverer Sir William Herschel, and Leverrier for the new planet. though it was used by anglophone institutions. Professor James Pillans of the University of Edinburgh defended the name Janus for the new planet, and proposed a key for its symbol. Meanwhile, Struve presented the name Neptune on December 29, 1846, to the Saint Petersburg Academy of Sciences. 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. The planetary symbol was Neptune's trident, with the handle stylized either as a cross , following Mercury, Venus and the asteroids, or as an orb , following the monograms for Uranus and Neptune. 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.
Athena (Pallas) with her lance and Poseidon (Neptune) with his trident. These weapons became the symbols of the planets Pallas and Neptune, respectively.
Stylized Neptune symbol (orb base)
Stylized Neptune symbol (cross base)
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. 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.
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Pluto symbol stylized as an inverted Mercury
Pluto holding a bident
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.
In the late 20th century, astrologers introduced replacement symbols for 4 Vesta (the sacred fire of Vesta, encoded U+26B6 ⚶ VESTA), 10 Hygiea (a caduceus – a common error in the USA for a staff of Asclepius – encoded U+2BDA ⯚ HYGIEA), Pluto (a bident, encoded U+2BD3 ⯓ PLUTO FORM TWO), and a symbol for 2060 Chiron, discovered in 1977 (a key, U+26B7 ⚷ CHIRON). Chiron's symbol was adapted for further centaurs discovered; symbols for 5145 Pholus and 7066 Nessus have been encoded in Unicode. The astrological symbol for Vesta is now universal, and that 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 future version 16.
|(⚳) CERES at U+26B3.|
|(⚴) PALLAS at U+26B4.|
|(⚵) JUNO at U+26B5.|
|(⚶) VESTA at U+26B6.|
|(⚷) CHIRON at U+26B7.|
|(⯛) PHOLUS at U+2BDB|
|(⯛) NESSUS at U+2BDC|
|(⯰) ERIS FORM ONE at U+2BF0|
|(⯱) ERIS FORM TWO at U+2BF1|
|(⯲) SEDNA at U+2BF2|
|() HAUMEA scheduled for U+1F77B|
|() MAKEMAKE scheduled for U+1F77C|
|() GONGGONG scheduled for U+1F77D|
|() QUAOAR scheduled for U+1F77E|
|() ORCUS scheduled for U+1F77F|
Ceres with her sickle
Juno with her scepter
Vesta's sacred fire
Petroglyph of Makemake
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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.
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.