In
classical antiquity, the seven classical planets or seven luminaries are the seven moving
astronomical object
An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists in the observable universe. In astronomy, the terms ''object'' and ''body'' are often us ...
s in the sky visible to the
naked eye: the
Moon,
Mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
,
Venus, the
Sun,
Mars,
Jupiter, and
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
. The word ''
planet'' comes from two related
Greek words, πλάνης ''planēs'' (whence πλάνητες ἀστέρες ''planētes asteres'' "wandering stars, planets") and πλανήτης ''planētēs'', both with the original meaning of "wanderer", expressing the fact that these objects move across the
celestial sphere
In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, ...
relative to the
fixed star
In astronomy, fixed stars ( la, stellae fixae) is a term to name the full set of glowing points, astronomical objects actually and mainly stars, that appear not to move relative to one another against the darkness of the night sky in the backg ...
s. Greek astronomers such as
Geminus and
Ptolemy often divided the seven planets into the Sun, the Moon, and the five planets.
The term ''planet'' in
modern terminology is only applied to
natural satellites directly orbiting the Sun (or other stars), so that only five of the seven classical planets are planets in the modern sense. The same seven planets, along with the ascending and descending lunar node, are mentioned in
Vedic astrology as the nine
Navagraha.
Babylonian astronomy
The Babylonians recognized seven planets. A bilingual list in the British Museum records the seven Babylonian planets in the following order:
In
Mandaeism, the names of the
Seven Planets are derived from the seven Babylonian planets.
Similarly, in
Syriac, all the planet names derive from the Babylonian planets in the
Akkadian language.
Symbols
The
astrological symbols for the classical planets appear in the medieval Byzantine codices in which many ancient horoscopes were preserved.
In the original papyri of these Greek horoscopes, there are found a circle with one ray (
![Old symbol for sun](https://upload.wikimedia.org/wikipedia/commons/4/45/Old_symbol_for_sun.svg)
) for the Sun and a crescent for the Moon.
The written symbols for Mercury, Venus, Jupiter, and Saturn have been traced to forms found in late Greek papyri.
The symbols for Jupiter and Saturn are identified as monograms of the initial letters of the corresponding Greek names, and the symbol for Mercury is a stylized caduceus.
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,
shows Greek personifications of planetary gods charged with early versions of the planetary symbols: Mercury has a
caduceus
The caduceus (☤; ; la, cādūceus, from grc-gre, κηρύκειον "herald's wand, or staff") is the staff carried by Hermes in Greek mythology and consequently by Hermes Trismegistus in Greco-Egyptian mythology. The same staff was also ...
; 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, pictured as a circle with a dot (☉), first appeared in the
Renaissance.
Planetary hours
The
Ptolemaic system used in
Greek astronomy placed the planets in order, closest to Earth to furthest, as the Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. In addition the day was divided into seven hour intervals, each ruled by one of the planets, although the order was staggered (see below).
The first hour of each day was named after the ruling planet, giving rise to the names and order of the Roman
seven-day week. 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.
The modern English days of the week were mostly inherited from gods of the old Germanic Norse culture – Wednesday is ''
Wōden''’s-day (''Wōden'' or ''Wettin'' eqv. Mercury), Thursday is ''
Thor''’s-day (Thor eqv. Jupiter), Friday is ''
Frige
Frigg (; Old Norse: ) is a goddess, one of the Æsir, in Germanic mythology. In Norse mythology, the source of most surviving information about her, she is associated with marriage, prophecy, clairvoyance and motherhood, and dwells in the w ...
''-day (Frige eqv. Venus). Equivalence here is by the gods' roles; for instance, Venus and Frige were both goddesses of love. It can be correlated that the Norse gods were attributed to each Roman planet and its god, probably due to Roman influence rather than coincidentally by the naming of the planets. A vestige of the Roman convention remains in the English name Saturday.
Alchemy
In alchemy, each classical planet (
Moon,
Mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
,
Venus,
Sun,
Mars,
Jupiter, and
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
) was associated with one of the seven metals known to the classical world (
silver,
mercury/quicksilver,
copper,
gold,
iron,
tin and
lead respectively). As a result, the
alchemical glyphs for the metal and associated planet coincide. Alchemists believed the other elemental metals were variants of these seven (e.g. zinc was known as "Indian tin" or "mock silver"
[Philip Ball, ''The Devil's Doctor: Paracelsus and the World of Renaissance Magic and Science'', ]).
Alchemy in the
Western World and other locations where it was widely practiced was (and in many cases still is) allied and intertwined with traditional Babylonian-Greek style astrology; in numerous ways they were built to complement each other in the search for
hidden knowledge (knowledge that is not common i.e. the occult).
Astrology has used the concept of
classical elements from antiquity up until the present day today. Most modern astrologers use the four classical elements extensively, and indeed they are still viewed as a critical part of interpreting the astrological chart.
Traditionally, each of the seven "
planets
A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young ...
" in the solar system as known to the ancients was associated with, held dominion over, and "ruled" a certain
metal (see also
astrology and the classical elements).
The list of
rulership is as follows:
* The
Sun rules
Gold ()
* The
Moon,
Silver ()
*
Mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
, Quicksilver/
Mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
()
*
Venus,
Copper ()
*
Mars,
Iron ()
*
Jupiter,
Tin ()
*
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
,
Lead ()
Some alchemists (e.g.
Paracelsus
Paracelsus (; ; 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance.
He w ...
) adopted the
Hermetic Qabalah assignment between the
vital organs and the planets as follows:
Contemporary astrology
Western astrology
Indian astrology
Indian astronomy and astrology (
Jyotiṣa) recognises seven visible planets (including the sun and moon) and two additional invisible planets(''tamo'graha'').
Chinese astronomy
The cycles of the
Chinese calendar
The traditional Chinese calendar (also known as the Agricultural Calendar 曆; 农历; ''Nónglì''; 'farming calendar' Former Calendar 曆; 旧历; ''Jiùlì'' Traditional Calendar 曆; 老历; ''Lǎolì'', is a lunisolar calendar ...
are linked to the orbit of Jupiter, there being 12 sacred beasts in the Chinese dodecannualar geomantic and astrological cycle, and 12 years in the orbit of Jupiter.
Naked-eye planets
Mercury and Venus are visible only in twilight hours because their orbits are interior to that of Earth. Venus is the third-brightest object in the sky and the most prominent planet. Mercury is more difficult to see due to its proximity to the Sun. Lengthy
twilight and an extremely low angle at maximum
elongations make optical filters necessary to see Mercury from extreme polar locations.
Mars is at its brightest when it is in
opposition, which occurs approximately every twenty-five months. Jupiter and Saturn are the largest of the five planets, but are farther from the Sun, and therefore receive less sunlight. Nonetheless, Jupiter is often the next brightest object in the sky after Venus. Saturn's luminosity is often enhanced by its rings, which reflect light to varying degrees, depending on their inclination to the
ecliptic; however, the rings themselves are not visible to the
naked eye from the Earth.
Uranus and sometimes the
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
Vesta are in principle visible to the naked eye on very clear nights, but, unlike the true naked-eye planets, are less luminous than thousands of stars, and as such, do not stand out enough for their existence to be noticed without the aid of a telescope.
Notes
See also
*
Antikythera mechanism
*
Aspects of Venus
In astrology, an aspect is an angle a planet makes to another planet or point of astrological interest. As the second-brightest object in the night sky after the Moon, often prominent during the morning or evening, Venus has aspects that are read ...
*
Astra Planeta
*
Behenian fixed star
The Behenian fixed stars are a selection of fifteen stars considered especially useful for magical applications in the medieval astrology of Europe and the Arab world. Their name derives from Arabic ''bahman'', "root," as each was considered a s ...
*
Celestial spheres
*
Definition of planet
*
Geocentric model
In astronomy, the geocentric model (also known as geocentrism, often exemplified specifically by the Ptolemaic system) is a superseded description of the Universe with Earth at the center. Under most geocentric models, the Sun, Moon, stars, an ...
*
List of Mesopotamian deities#Major deities
*
List of former planets
*
Wufang Shangdi
References
External links
The Naked Eye Planets and how to identify them*
ttp://www.nineplanets.org/history.html Chronology of Discoveries in the Solar System
{{DEFAULTSORT:Classical Planet
Ancient astronomy
Planets of the Solar System