A classical planet is an astronomical object that is visible to the naked eye and moves across the sky and its backdrop of fixed stars (the common stars which seem still in contrast to the planets). Visible to humans on Earth there are seven classical planets (the seven luminaries). They are from brightest to dimmest: the Sun, the Moon, Venus, Jupiter, Mars, Mercury and Saturn.
Greek astronomers such as Geminus and Ptolemy recorded these classical planets during classical antiquity, introducing the term planet, which means 'wanderer' in Greek (Greek, Ancient (to 1453);: πλάνης and Greek, Ancient (to 1453);: πλανήτης), expressing the fact that these objects move across the celestial sphere relative to the fixed stars.[1] [2] Therefore, the Greeks were the first to develop the astrological connections to the planets' visual detail.
Through the use of telescopes other celestial objects like the classical planets were found, starting with the Galilean moons in 1610. Today the term planet is used considerably differently, with a planet being defined as a natural satellite directly orbiting the Sun (or other stars) and having cleared its own orbit. Therefore, only five of the seven classical planets remain recognized as planets, alongside Earth, Uranus, and Neptune.
See main article: Babylonian astronomy.
The Babylonians recognized seven planets. A bilingual list in the British Museum records the seven Babylonian planets in the following order:[3]
See main article: Mandaean cosmology. In Mandaeism, the names of the seven planets are derived from the seven Babylonian planets.[4] Overall, the seven classical planets (ࡔࡅࡁࡀ|šuba|The Seven; ࡔࡉࡁࡉࡀࡄࡉࡀ, "planets"; or, combined, "Seven Planets"[5]) are generally not viewed favorably in Mandaeism, since they constitute part of the entourage of Ruha, the Queen of the World of Darkness who is also their mother. However, individually, some of the planets can be associated with positive qualities. The names of the seven planets in Mandaic are borrowed from Akkadian.[4] Some of the names are ultimately derived from Sumerian, since Akkadian had borrowed many deity names from Sumerian.
Each planet is said to be carried in a ship. Drawings of these ships are found in various Mandaean scriptures, such as the Scroll of Abatur. The planets are listed according to the traditional Mandaean order of the planets as mentioned in Masco (2012).[6]
| Planet | Mandaic | Mandaic script | Akkadian | Other names | Associations | |
|---|---|---|---|---|---|---|
| Sun | Šamiš | ࡔࡀࡌࡉࡔ | Šamaš | Adunai ← Hebrew Adonai | light and life-powers Yawar Ziwa (Dazzling Light) and Simat Hayyi (Treasure of Life); Yazuqaeans[7] | |
| Venus | Libat | ࡋࡉࡁࡀࡕ | Delebat | Amamit (the underworld goddess), Argiuat, Daitia, Kukbat (the diminutive of 'star'), Spindar, ʿstira (i.e., Ishtar or Astarte), and Ruha or Ruha ḏ-qudša (Holy Spirit) | success in love and reproduction | |
| Mercury | Nbu (ʿNbu) | ࡍࡁࡅ ࡏࡍࡁࡅ | Nabû | Maqurpiil, Mšiha ← Messiah; ʿaṭarid ← Arabic | learning, scribes; Christ and Christianity | |
| Moon | Sin | ࡎࡉࡍ | Sīnu | Agzʿil, Ṭaṭmʿil, Ṣaurʿil, and Sira | miscarriages and abnormal births | |
| Saturn | Kiwan | ࡊࡉࡅࡀࡍ | Kayyamānu | Br Šamiš (The Son of the Sun) | Jews; Saturday | |
| Jupiter | Bil | ࡁࡉࡋ | Bēlu | Angʿil | male; "hot and moist" | |
| Mars | Nirig | ࡍࡉࡓࡉࡂ | Nergallu | Marik | violence; Islam |
See main article: article, Astrological symbols and Planet symbols.
The astrological symbols for the classical planets appear in the medieval Byzantine codices in which many ancient horoscopes were preserved.[8] 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.[9] The written symbols for Mercury, Venus, Jupiter, and Saturn have been traced to forms found in late Greek papyri.[10] 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,[11] 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.[12] 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.[9]
See main article: article, Planetary hours and Names of the days of the week. 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.[13] 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-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.
| Weekday | Planet | Greek god | Germanic god | Weekday | ||
|---|---|---|---|---|---|---|
| French name | Roman god | Greek name | Norse name | Saxon name | English name | |
| dimanche | Sol | Helios | Sól | Sunne | Sunday | |
| lundi | Luna | Selene | Máni | Mōnda | Monday | |
| mardi | Mars | Ares | Týr | Tīw | Tuesday | |
| mercredi | Mercury | Hermes | Óðinn | Wōden / Wettin | Wednesday | |
| jeudi | Jupiter | Zeus | Þórr | Thunor | Thursday | |
| vendredi | Venus | Aphrodite | Frigg | Frige | Friday | |
| samedi | Saturn | Cronus | Njörðr[14] | Njord | Saturday | |
In alchemy, each classical planet (Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn) 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"[15]).
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" 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:
Some alchemists (e.g. Paracelsus) adopted the Hermetic Qabalah assignment between the vital organs and the planets as follows:[15]
| Planet | Organ | |
| Sun | Heart | |
| Moon | Brain | |
| Mercury | Lungs | |
| Venus | Kidneys | |
| Mars | Gall bladder | |
| Jupiter | Liver | |
| Saturn | Spleen |
See main article: article and Planets in astrology.
| Planet | Domicile sign(s)[16] | Detriment sign(s) | Exaltation sign[17] | Fall sign | |
|---|---|---|---|---|---|
| Sun | Leo | Aquarius | Aries | Libra | |
| Moon | Cancer | Capricorn | Taurus | Scorpio | |
| Mercury | Gemini (diurnal) and Virgo (nocturnal) | Sagittarius (diurnal) and Pisces (nocturnal) | Virgo | Pisces | |
| Venus | Libra (diurnal) and Taurus (nocturnal) | Aries (diurnal) and Scorpio (nocturnal) | Pisces | Virgo | |
| Mars | Aries (diurnal) and Scorpio (nocturnal) | Libra (diurnal) and Taurus (nocturnal) | Capricorn | Cancer | |
| Jupiter | Sagittarius (diurnal) and Pisces (nocturnal) | Gemini (diurnal) and Virgo (nocturnal) | Cancer | Capricorn | |
| Saturn | Aquarius (diurnal) and Capricorn (nocturnal) | Leo (diurnal) and Cancer (nocturnal) | Libra | Aries |
See main article: article and Navagraha.
Indian astronomy and astrology (jyotiṣa) recognises seven visible planets (including the Sun and Moon) and two additional invisible planets(tamo'graha); rahu and ketu.[18] [19]
| Sanskrit Name | English Name | Nakshatras | Represents | Day | ||
|---|---|---|---|---|---|---|
| Surya (सूर्य) | Krittika, Uttara Phalguni and Uttara Ashadha | Soul, king, highly placed persons, father, ego | Sunday | |||
| Chandra (चंद्र) | Rohini, Hasta and Shravana | Emotional Mind, queen, mother. | Monday | |||
| Mangala (मंगल) | Mrigashira, Chitra and Dhanishta | Tuesday | ||||
| Budha (बुध) | Ashlesha, Jyeshta and Revati | Communication and analysis, mind | Wednesday | |||
| Brihaspati (बृहस्पति) | Punarvasu, Vishakha and Purva Bhadrapada | Sattva | the great teacher, wealth, Expansion, progeny | Thursday | ||
| Shukra (शुक्र) | Bharani, Purva Phalguni and Purva Ashadha | Rajas | Feminine, pleasure and reproduction, Luxury, Love, Spouse | Friday | ||
| Shani (शनि) | Pushya, Anuradha and Uttara Bhadrapada | learning the hard way. Career and Longevity, Contraction | Saturday | |||
| Rahu (राहु) | Ardra, Swati and Shatabhisha | an Asura who does his best to plunge any area of one's life he controls into chaos, works on the subconscious level | none | |||
| Ketu (केतु) | Descending/South Lunar Node | Ashwini, Magha and Mula | supernatural influences, works on the subconscious level | none |
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.[20] 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.