A planet symbol or planetary symbol is a graphical symbol used in astrology and astronomy to represent a classical planet 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. Most of the symbols originated in Greco-Roman astronomy; their modern forms developed in the 16th century.
Early modern depiction of the planet symbols in an alchemical context (Musaeum Hermeticum, 1678)
Page spread (with the signs for Mars and Venus) from a 1515 illustrated edition of Abu Ma'shar al-Balkhi's De Magnis Coniunctionibus (in the by translation by Herman of Carinthia, c. 1140, editio princeps by Erhard Ratdolt of Augsburg, 1489).
16th-century mechanical clock + calendar, using the symbols of the eponymous planets for the days of the week.
Planetary-metal symbols at the center of the coat of arms of the Royal Society of Chemistry
Historically, astrological and astronomical symbols have overlapped. Frequently used symbols include signs of the zodiac and classical planets. These originate from medieval Byzantine codices. Their current form is a product of the European Renaissance. Other symbols for astrological aspects are used in various astrological traditions.
A mid-18th-century manuscript with symbols for the signs and planets. Note the distinctive shapes of Virgo (6), Scorpio (8), Capricorn (10) and Aquarius (11).
