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| equatorial radius: | | 2.56×104 km |
| polar radius: | 2.50×104 | ||
| mass: | 8.70×1025 kg | ||
| density: | 1.25 g/cm3 | ||
| shortest distance from sun: | 2.72×109 km | ||
| average distance from sun: | 2.87×109 km | ||
| greatest distance from sun: | 3.00×109 km | ||
| orbital eccentricity: | 0.047 | ||
| tilt of axis to orbit: | 97.92° | ||
| orbital inclination to ecliptic: | 0.77° | ||
| length of day: | 17:14 (hr:min) | ||
| length of year: | 84.01 yr | ||
| temperature: | -216° C | ||
| atmospheric pressure: | 1.18 atm | ||
| atmospheric composition: | H2 (82%), He (15%), CH4 (2%), C2H2 | ||
| satellites: | Ariel
Belinda Bianca Cordelia Cressida Desdemona Juliet Miranda Oberon Ophelia Portia Puck Rosalind Titania Umbriel |
Discovered in 1781 by William Herschel, Uranus is named for the Greek personification of heaven and the ruler of the world. Uranus is over four times the size of Earth. Uranus is a very cold planet due to its huge distance from the Sun.
Uranus's orbit is a unique one. The inclination of its axis is 98 degrees, which means that at certain times in its orbit, one of the planets poles is pointing directly toward the Sun! Believe it or not, the poles actually get the most direct exposure to the sun's heat, so they are the warmest spots on the planet.
Uranus is the third planet in our solar system that has been found to have a system of rings. The rings were discovered by accident by scientists in 1977 who were observing an unrelated star. Uranus has several rings. The rings are much different from those of Saturn in several ways. First, Uranus's rings are much darker and thinner than Saturn's. Second, the particles in Uranus's rings are more like coal dust, while Saturn's rings consist of icy, more reflective particles. Lastly, the rings around Uranus are much closer to the planet itself than Saturn's. All these factors add up to explain why no one noticed Uranus's rings for so long.
Uranus has fifteen known moons. The major ones are, in order of nearest to farthest, Miranda, Ariel, Unbriel, Titania, and Oberon. The two largest and brightest are Titania and Oberon. Little is known about the moons because they are so small and far away.
The Planet Uranus - Data
The Planet Uranus - Info & lots of facts
Uranus: The Tilted Planet - Info
* Photo credit - NSSDC
