|a planet of the solar system, as opposed to an asteroid (minor planet)|
|1.||Also called: major planet any of the eight celestial bodies, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, that revolve around the sun in elliptical orbits and are illuminated by light from the sun|
|2.||Also called: extrasolar planet any other celestial body revolving around a star, illuminated by light from that star|
|3.||astrology See also house any of the planets of the solar system, excluding the earth but including the sun and moon, each thought to rule one or sometimes two signs of the zodiac|
|[C12: via Old French from Late Latin planēta, from Greek planētēs wanderer, from planaein to wander]|
planet [%PREMIUM_LINK%] (plān'ĭt) Pronunciation Key |
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 moon—and 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 planet, inner planet, outer planet.
An object in orbit around a star. A planet does not give off its own light; rather, it shines by reflecting sunlight. Planets close to the sun are rocky. Those farther out consist mostly of gases and liquids.
Note: There are nine major planets, including the Earth, in orbit around our sun, along with many asteroids. (See solar system.)
Note: Scientists have discovered evidence for the existence of many planets that circle other stars.