Uranus science definition

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.