plan·et (pl n  t)n. 1. a. In the traditional model of solar systems, a celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves. b. A celestial body that orbits the sun, has sufficient mass to assume nearly a round shape, clears out dust and debris from the neighborhood around its orbit, and is not a satellite of another planet. 2. One of the seven celestial bodies, Mercury, Venus, the moon, the sun, Mars, Jupiter, and Saturn, visible to the naked eye and thought by ancient astronomers to revolve in the heavens about a fixed Earth and among fixed stars. 3. One of the seven revolving astrological celestial bodies that in conjunction with the stars are believed to influence human affairs and personalities. [Middle English, from Old French planete, from Late Latin plan  ta, from Greek plants, variant of plans, plant-, from plan sthai, to wander; see pel -2 in Indo-European roots.]Usage Note: Clyde Tombaugh's discovery of Pluto in 1930 added a ninth planet to our solar system, and thereafter students of astronomy were taught the familiar list of nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. But in 2006, the International Astronomical Union (IAU) voted to change the definition of planet, requiring that a clestial body must have enough mass to assume a round shape and "clear the neighborhood around its orbit" in order to qualify as a planet. This means that a planet cannot have other objects in or crossing its orbit except smaller objects that have been captured by its gravity, such as those that revolve around it as moons. Because Neptune's large mass has captured Pluto so that the two planets remain in orbits that cross, Pluto has not cleared its own orbit and was therefore demoted from planet status to that of a newly created category, dwarf planet. Like a planet, a dwarf planet orbits the sun, is large enough to assume a nearly round shape, and does not orbit a planet (as our Moon does). But a dwarf planet does not clear the neighborhood around its orbit and may cross the paths of other objects orbiting the sun. Other dwarf planets include Ceres, whose orbit is in the asteroid belt betwen Mars and Jupiter, and Eris, an object in the Kuiper belt beyond Pluto. At the same meeting the IAU created a third category of objects known as small solar system bodies, which includes asteroids (sometimes referred to as "minor planets," compounding the difficulty of the term planet,) comets, objects beyond Netpune's orbit, and other nonspherical bodies. Although officially approved, this new scheme of the solar system remains controversial among astronomers and may well be revised. |   |
planet
Noun
any of the nine celestial bodies, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, or Pluto, that revolve around the sun in oval-shaped orbits [Greek planaein to wander]
planetary adj
| planet (plnt) A large celestial body, smaller than a star but larger than an asteroid, that does not produce its own light but is illuminated by light from the star around which it revolves. In our solar system there are nine known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Because of Pluto's small size  about two-thirds the diameter of Earth's moonand its unusual orbit, many astronomers believe it should actually be classed as a Kuiper belt object rather than a planet. A planetlike body with more than about ten times the mass of Jupiter would be considered a brown dwarf rather than a planet. See also extrasolar planetinner planetouter planetplanetary adjective |
ThesaurusLegend: Synonyms Related Words Antonyms
| Noun | 1. |  planet - (astronomy) any of the nine large celestial bodies in the solar system that revolve around the sun and shine by reflected light; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto in order of their proximity to the sun; viewed from the constellation Hercules, all the planets rotate around the sun in a counterclockwise directionastronomy, uranology - the branch of physics that studies celestial bodies and the universe as a whole biosphere - the regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist celestial body, heavenly body - natural objects visible in the sky inferior planet - any of the planets whose orbit lies inside the earth's orbit gas giant, Jovian planet - any of the four outermost planets in the solar system; much larger than Earth and gaseous in nature (like Jupiter) daystar, morning star, Phosphorus, Lucifer - a planet (usually Venus) seen just before sunrise in the eastern sky outer planet - (astronomy) a major planet whose orbit is outside the asteroid belt (Jupiter, Saturn, Uranus, Neptune, Pluto) solar system - the sun with the celestial bodies that revolve around it in its gravitational field superior planet - any of the planets whose orbit lies outside the earth's orbit terrestrial planet - a planet having a compact rocky surface like the Earth's; the four innermost planets in the solar system |
| 2. | planet - a person who follows or serves another follower - a person who accepts the leadership of another | |
| 3. | planet - any celestial body (other than comets or satellites) that revolves around a star celestial body, heavenly body - natural objects visible in the sky |
Translations
n planet [ˈplӕnit]
any of the bodies (eg the Earth) which move round the Sun or round another star Mars and Jupiter are planets, but the Moon is not. planeet كوكَب سَيّار планета planeta planet der Planet πλανήτης planeta planeet سیاره planeetta planète כּוֹכָב לֶכֶת ग्रह planet bolygó planet pláneta, reikistjarna pianeta 惑星 행성 planeta planēta planet planeet planet planeta planeta planetă планета planéta planet planeta planet โลกดาวเคราะห์ gezegen 行星 планета سيارہ، جرم فلکي hành tinh 行星
adj planetary
planetêr كَوْكَبي، سَيّاري планетен planetární planetarisk; planet- planetarisch πλανητικός planetario planetaar- وابسته به سیاره planeetta- planétaire שֶׁל כּוֹכבי לֶכֶת ग्रहीय planetarni bolygó- planetarium reikistjörnu- planetario 惑星の 행성의 planetinis, planetų planētas-; planētu- planet planetair planet-, planetarisk planetarny planetário planetar планетный;планетарный planetárny planeten planetarni planetarisk, planet- เกี่ยวกับโลกดาวเคราะห์ gezegenle ilgili 行星的 планетний; планетарний سياروں سے متعلق thuộc về hành tinh 行星的
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