r-uh-nuh
s, yoo-rey-]
| 1. | Astronomy. the planet seventh in order from the sun, having an equatorial diameter of 32,600 miles (56,460 km), a mean distance from the sun of 1,784 million miles (2,871 million km), a period of revolution of 84.07 years, and 15 moons. |
| 2. | Also, Ouranos. Classical Mythology. the personification of Heaven and ruler of the world, son and husband of Gaea (Earth) and father of the Titans, who was castrated and dethroned by his youngest son, Cronus, at the instigation of Gaea. |
In astronomy, the seventh major planet from the sun, named for the Greek god of the sky. Uranus was the first planet discovered in modern times (1781). (See solar system.)
"I cannot but wish to take this opportunity of expressing my sense of gratitude, by giving the name of Georgium Sidus ... to a star which (with respect to us) first began to shine under His auspicious reign." [Sir William Herschel, 1783]The planet was known in Eng. in 1780s as the Georgian Planet; Fr. astronomers began calling Herschel, and ult. Ger. astronomer Johann Bode proposed Uranus as in conformity with other planet names. However, the name didn't come into common usage until c.1850.
Uranus (y r'ə-nəs, y -rā'-) Pronunciation Key
The seventh planet from the Sun and the third largest, with a diameter about four times that of Earth. Though slightly larger than Nepture, Uranus is the least massive of the four gas giants and is the only one with no internal heat source. A cloud layer of frozen methane gives it a faint bluish-green color, and it is encircled by a thin system of 11 rings and 27 moons. Uranus's axis is tilted 98° from the vertical—the greatest such tilt in the solar system—with the result that its poles are in continuous darkness or continuous sunlight for nearly half of its 84-year orbital period. See Table at solar system. |
Uranus
Hideyuki Nakashima
(ftp://etlport.etl.go.jp/pub/uranus/ftp).