Classical planet

Greek astronomers such as Geminus[1] and Ptolemy[2] recorded these classical planets during classical antiquity, introducing the term planet, which means 'wanderer' in Greek (πλάνης planēs and πλανήτης planētēs), expressing the fact that these objects move across the celestial sphere relative to the fixed stars.

[9]: 87 The astrological symbols for the classical planets appear in the medieval Byzantine codices in which many ancient horoscopes were preserved.

[11] In the original papyri of these Greek horoscopes, there are found a circle with one ray () for the Sun and a crescent for the Moon.

[12] The written symbols for Mercury, Venus, Jupiter, and Saturn have been traced to forms found in late Greek papyri.

[13] A. S. D. Maunder finds antecedents of the planetary symbols in earlier sources, used to represent the gods associated with the classical planets.

Bianchini's planisphere, produced in the 2nd century,[14] 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.

[15] 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.

[12] The Ptolemaic system used in ancient Greek astronomy placed the planets by order of proximity to Earth in the then-current geocentric model, closest to furthest, as the Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn.

Modern Latin-based cultures, in general, directly inherited the days of the week from the Romans and they were named after the classical planets; for example, in Spanish Miércoles is Mercury, and in French mardi is Mars-day.

Alchemists believed the other elemental metals were variants of these seven (e.g. zinc was known as "Indian tin" or "mock silver"[18]).