Uranus orbits the Sun on its side. Its south pole is pointed towards Earth. The angle of the tilt of the axis of Uranus is 97 degrees. This is probably due to an object the size of Earth smashing into Uranus during its formation billions of years ago.
Voyager 2 was the first manmade object to reach Uranus. It had previously visited Jupiter and Saturn and had taken exciting close-up images of those two planets and their moons. However, when the first pictures of Uranus from Voyager 2 were received on Earth in January 1986, scientists were disappointed to see that it was a pale blue, featureless world. Six years of waiting and all they saw were images like the one on the left!
Uranus' pale blue colour is caused by the methane in its atmosphere which filters out red light.
If we were able to see Uranus' moons orbiting the planet, they would go over and under the planet like lights on a ferris wheel.
Uranus has 27 moons (so far discovered) orbiting the planet. Ten of these were discovered in 1986 by the Voyager 2 mission.
A day on Uranus is a few hours shorter than a day on Earth - the planet takes 17 hours to spin on its axis. However, a year on Uranus is much longer than a year on Earth. In fact, it takes 84 years on Earth for Uranus to complete one orbit around the Sun!
Uranus was the first planet in the Solar System to be "discovered". The planets known of at the time of the discovery of Uranus were Mercury, Venus, Earth, Mars, Jupiter and Saturn. Ancient astronomers were able to see these objects without telescopes or binoculars and named them after their Gods. Uranus was discovered much later using scientific instruments, in 1781, but was still named after an ancient god (in mythology, Uranus was the ruler of the Gods)
Almost all of the moons of Uranus are named after characters in plays written by Shakespeare. The moons of every other planet in the Solar System are named after characters in Greek and Roman mythology. The two moons of Uranus that are not named after Shakespearean characters (Arlel and Umbriel) are named after characters in a book called "The Rape of the Lock" written by Alexander Pope.
|Meaning of Name||Uranos was the ancient Greek deity of the sky, grandfather of Zeus (Jupiter), father of Cronos (Saturn) and son of Gaia.|
|Name in Foreign Languages||Uranus (French, German, Latin), Urano (Spanish, Portuguese, Italian), Uran (Russian), Uranos (Greek)|
|Average Distance from the Sun||
2,870,658,186 km / 1,783,744,300 miles / 19.229 A.U.
Comparison with Earth: 149,597,890 km / 92,955,820 miles / 1.000 A.U.
|Closest Distance to the Sun (Perihelion)||
/ 1,699,449,110 miles / 18.280 A.U.
Comparison with Earth: 147,100,000 km / 91,400,000 miles / 0.983 A.U.
|Farthest Distance from the Sun (Aphelion)||
3,006,318,143 km / 1,868,039,489 miles / 20.083 A.U.
Comparison with Earth: 152,100,000 km / 94,500,000 miles / 1.017 A.U.
|Diameter across equator||51,118 km / 31,763 miles
Comparison with Earth: 12,756 km / 7,926 miles
|Diagram showing planet's size compared to the size of Earth|
|Circumference around equator||
159,354 km / 99,018 miles
Comparison with Earth: 40,074 km / 24,901 miles
Comparison with Earth: 5,973,700,000,000,000,000,000,000 kg
|Time to spin on Axis||17 hours, 14 minutes (in retrograde)
Comparison with Earth: 23 hours, 56 minutes
|Time to orbit the Sun||84 years
Comparison with Earth: 365 days, 6 hours
|Distance planet travels to complete one orbit||18,026,802,831 km / 11,201,335,967 miles
Comparison with Earth: 924,375,700 km / 574,380,400 miles
|Gravity (Earth = 1)||0.91
|Escape Velocity||76,968 km/h /47,826 mph
Comparison with Earth: 40,248 km/h / 25,009 mph
|Temperature at Cloud Tops||-216 °c / -357 °F / 57 K
Comparison with Earth's average temp: 15 °c / 59 °F / 288 K
|Contents of Atmosphere||Hydrogen, Helium, Methane|
|Known moons||There are at least 27 moons known to orbit Uranus - Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Cupid, Belinda, Perdita, Puck, Mab, Miranda, Ariel, Umbriel, Titania, Oberon, Francisco, Caliban, Stephano, Trinculo, Sycorax, Margaret, Propero, Setebos and Ferdinand|
|Past Missions (including nationality and year of launch)||None|
|Present Missions||Voyager 2 (USA,
Note that although this is still an active missions, it has long since visited Uranus and is active in a completely different region in space.
|Proposed or planned Missions||There are no proposed missions to Uranus|