Planet symbols
A planet symbol is a graphical symbol used in astrology and astronomy to represent a classical planet or one of the eight modern planets. The symbols are also used in alchemy to represent the metals that are associated with the planets. The use of these symbols is based in ancient Greco-Roman astronomy, although their current shapes are a development of the 16th century.
The classical planets with their symbols and associated metals are:
| planet | Moon | Mercury | Venus | Sun | Mars | Jupiter | Saturn |
| symbol | |||||||
| metal | silver | mercury | copper | gold | iron | tin | lead |
The International Astronomical Union 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:
| planet | Mercury | Venus | Earth | Mars | Jupiter | Saturn | Uranus | Neptune |
| symbol | ||||||||
| IAU | Me | V | E | Ma | J | S | U | N |
The symbols of Venus and Mars are also used to represent female and male in biology and botany, following a convention introduced by Linnaeus in the 1750s.
History
Classical planets
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 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 shows the Sun represented by the circle with a ray, Jupiter by the letter zeta, Mars by a shield crossed by a spear, and the remaining classical planets by symbols resembling the modern ones, without the cross-mark seen in modern versions of the symbols. 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.
Earth symbol
is not one of the classical planets.Its status as planet is a consequence of the development of heliocentrism.
Nevertheless, there are ancient symbols for Earth, notably a cross representing the four cardinal directions, as a cross in a circle also interpreted as a globe with equator and a meridian;
This "Earth" symbol is encoded by Unicode at U+1F728. In other contexts the same symbol represents the Sun and has been given the name Sun cross in modern times.
Alternatively, the globus cruciger ♁, the globe surmounted by a Christian cross, has a long tradition in Christendom as the planetary symbol for Earth..
Modern discoveries
, also :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, ☉. This symbol also combines the symbols of Mars and the Sun because in Greek Mythology, Uranus represented heaven, and represents the combined power of Mars' spear and the Sun.
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".
Neptune , Neptune's trident, also to accompany the suggested names for the planet. Claiming the right to name his discovery, Urbain Le Verrier originally proposed the name 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 stiff 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. 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.
Pluto was also considered a planet from its discovery in 1930 until its re-classification as a "dwarf planet" in 2006. The symbol used for Pluto was a ligature of the letters P and L.
In the 19th century, symbols for the major asteroids were also in use, including
Vesta, Juno, Ceres, Pallas ;
Encke has further symbols for Astraea, Hebe, Iris, Flora and Metis.
Unicode furthermore has a symbol for 2060 Chiron.
Classical planets
Moon
The crescent shape has been used to represent the Moon since earliest times. In classical anqituity, it is worn by lunar deities either on the head or behind the shoulders, with its horns pointing upward.Its representation with the horns pointing sideways is early modern.
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", "waxing", "full moon" and "waning".
Mercury
The symbol for Mercury is ultimately derived from the caduceus, or intertwined serpents, which were the main attribute of Mercury/Hermes throughout antiquity.The caduceus was usually shown with at least three loops, but this was simplified to a single loop in the diagram of Kamateros.
The modern symbol has also been interpreted as representing the god's winged headdress.
Venus
The Venus symbol consists of a circle with a small cross below it.It originates from an evolution of the initial letter of the Ancient Greek name of the planet, and was adopted in Late Antiquity as an astrological symbol for the planet Venus, and hence as an old and obsolete alchemical symbol for copper. In modern times, it is still used as the astronomical symbol for Venus, although its use is discouraged
by the International Astronomical Union.
In botany and biology, it is used to represent the female 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.
The symbol appears without the cross-mark in Johannes Kamateros. In the Bianchini's planisphere, Venus is represented by a necklace.
The idea that the symbol represents the goddess's hand mirror was introduced by Joseph Justus Scaliger in the late 16th century. Claudius Salmasius, in the early 17th century, established that it derived from the Greek abbreviation for Phosphoros, the planet's name.
Unicode encodes the FEMALE SIGN at U+2640, in the Miscellaneous Symbols block.
Sun
The modern astronomical symbol for the Sun was first used in the Renaissance.Bianchini's planisphere, produced in the 2nd century, has a circlet with rays radiating from it.
A diagram in Johannes Kamateros' 12th century Compendium of Astrology shows the Sun represented by a circle with a ray. This older symbol is encoded by Unicode as "ALCHEMICAL SYMBOL FOR GOLD" in the Alchemical Symbols block.
Mars
The Mars symbol is a depiction of a circle with an arrow emerging from it, pointing at an angle to the upper right. 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, following a convention introduced by Linnaeus in the 1750s.The symbol in its current form represents spear and shield and dates to the early 16th century. It is derived from a medieval form where the spear was drawn across the shield, which in turn was based on a convention used in antiquity which represented Mars by a spear.
A diagram in the 12th-century Compendium of Astrology by Johannes Kamateros represents Mars by a shield crossed by a spear.
Jupiter
The origin of the symbol for Jupiter is not entirely clear.Jupiter's attribute is a sceptre , but Kamateros represents Jupiter simply by the letter zeta ζ. The modern symbol as used from the 16th century is apparently based on a majuscule zeta with the addition of a vertical stroke to form the Christian cross. The less-than-intuitive symbol gave rise to various ad hoc interpretations by modern commentators; thus, the editors of the Penny cyclopedia thought might "supposed to be a symbol of the thunder " and more recently the sign has been reported as based on the "Egyptian hieroglyph for the eagle".