Symbols for the
classical planets, zodiac signs, aspects, lots, and the lunar nodes appear in the medieval Byzantine codices in which many ancient horoscopes were preserved. In the original Greek horoscope papyri, the Sun was depicted by a circle bearing the ancient glyph for radiance (), while the Moon was symbolized by a crescent.
Classical planets The written symbols for Mercury, Venus, Jupiter, and Saturn have been traced to forms found in late Classical Greek papyri. The symbols for Jupiter and Saturn are monograms of the initial letters of the corresponding Greek names, and the symbol for Mercury is a stylized
caduceus. shows Greek personifications of planetary gods charged with early versions of the planetary symbols: Mercury has a
caduceus; Venus has, attached to her necklace, a cord connected to another necklace; Mars, a spear; Jupiter, a staff; Saturn, a scythe; the Sun, a
circlet with rays radiating from it; and the Moon, a headdress with a crescent attached. A diagram in Johannes Kamateros' 12th-century
Compendium of Astrology 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, without the cross-mark seen in modern versions of the symbols. The modern sun symbol resembles the Egyptian
hieroglyph for "sun" – a circle that sometimes had a dot in the center, (). Similar in appearance were several variants of the ancestral form of the modern Chinese
logograph for "sun", which in the
oracle bone script and
bronze script were . It is not known if the Egyptian and Chinese logographs have any connection to the European astrological symbol.
Major planets discovered in the modern era Symbols for Uranus, Neptune and Pluto were created shortly after their discovery. For Uranus, two variant symbols are seen. One symbol, , invented by
J. G. Köhler and refined by
Bode, was intended to represent the newly discovered metal
platinum; since platinum, sometimes described as white gold was found by chemists mixed with iron, the symbol for platinum combines the alchemical symbols for
iron, ♂, and
gold, ☉. An inverted version of that same symbol, was in use in the early 20th century. Another symbol, , was suggested by
Jérôme Lalande in 1784. In a letter to
William Herschel, Lalande described it as "a globe surmounted by the first letter of your name" (). After Neptune was discovered, the
Bureau des Longitudes proposed the name Neptune and the familiar trident for the planet's symbol, though at bottom may be either a cross or an orb .
Pluto, like Uranus, has multiple symbols in use. One symbol, ♇, is a
monogram of the letters
PL (which can be interpreted to stand for Pluto or for astronomer
Percival Lowell), was announced with the name of the new planet by the discoverers on May 1, 1930. Another symbol, popularized in Paul Clancy's
American Astrology magazine, is based on Pluto's
bident: .
Asteroids The astrological symbols for the first four objects discovered at the beginning of the 19th century —
Ceres,
Pallas,
Juno and
Vesta — were created shortly after their discoveries. They were initially listed as planets, and half a century later came to be called asteroids, though such "minor planets" continued to be considered planets for perhaps another century. Shortly after
Giuseppe Piazzi's discovery of
Ceres, a group of astronomers ratified the name, proposed by the discoverer, and chose the sickle as a symbol of the planet. The symbol for Pallas, the spear of
Pallas Athena, was invented by Baron Franz Xaver von Zach, and introduced in his
Monatliche Correspondenz zur Beförderung der Erd- und Himmels-Kunde.
Karl Ludwig Harding, who discovered and named Juno, assigned to it the symbol of a scepter topped with a star. The modern astrological form of the symbol for Vesta, ⚶, was created by Eleanor Bach, who is credited with pioneering the use of the
big four asteroids with the publication of her
Ephemerides of the Asteroids in the early 1970s. The original form of the symbol for Vesta, , was created by German mathematician
Carl Friedrich Gauss. Olbers, having previously discovered and named one new planet (as the asteroids were then classified), gave Gauss the honor of naming his newest discovery. Gauss decided to name the planet for the goddess
Vesta, and also specified that the symbol should be the altar of the goddess with the
sacred fire burning on it. Bach's variant is a simplification of 19th-century elaborations of Gauss's altar symbol. A widely used convention for other
centaurs, proposed by Robert von Heeren in the 1990s, is to replace the K of the Chiron key glyph with the initial letter of the object: e.g. P or
φ for Pholus and N for Nessus (, ).
Other trans-Neptunian objects Symbols for other large trans-Neptunian objects have mostly been proposed on the Internet; some created by Denis Moskowitz have been used by NASA and are used by the popular open-source astrological software
Astrolog, as well as being used less consistently by commercial programs.
Miscellaneous orbital stations The symbol for
retrograde motion is , a capital 'R' with a tail stroke. An 'R' with a tail stroke was used to
abbreviate many words beginning with the letter 'R'; in medical prescriptions, it abbreviated the word
recipe), and in
missals, an R with a tail stroke marked the responses. ==Meanings of the symbols==