Image of Uranus from:
NASA's Solar System Exploration Uranus Page


Uranus pronounced (yoor-uh-nuhs) is the seventh planet from the sun in our solar system and the third largest. Uranus was originally discovered in 1690 by John Flamsteed and labeled it "34 Tauri". Though John saw "34 Tauri" (Uranus) in the sky, he did not know that what he saw was a planet, what he believed though was that what he saw was a star. On March 13, 1781, William Herschel using an optical telescope observed Uranus in the sky. William named what he saw "Georgium Sidus" which means Georgian Planet. William named the planet after King George III of England, his patron. The planet was also commonly called "Herschel" after its founder. In 1850 the planets name was changed to Uranus to coincide with the with the naming tradition of naming discovered planets after Roman mythological gods.

Planetary Characteristics

Uranus as a planet believed to be composed of a liquid and solid matter along with gaseous outer layer. The outer layer / atmosphere of the planet consists of 83% Hydrogen gas, 15% Helium gas and 2% methane. This is the coldest layer of the planet at 53 Kelvin or -364 º Fahrenheit. Below the atmosphere is the outer liquid layer of the planet. This layer of the planet consists of liquid Hydrogen and liquid Helium. Below this outer liquid layer is another liquid layer that is almost completely solid and consists of icy water, ammonia and methane. Below the liquid layers is the core of the planet. The core is a little larger than the size of earth with a diameter of 10,500 miles where earth has a diameter of 7,922 miles. The core of the planet would consist of hot molten silicate rock at a temperature of 12,500º Fahrenheit.Uranus orbits the sun once every eighty four earth years. One rotation around the planets axis takes about 17 hours and 14 minutes. Uranus has an axial tilt of 97.77 degrees and due to this high degree of axial tilt, the planets has about 42 earth years of sunlight and 42 earth years of darkness at the poles.

Uranus' Rings

Image of Uranus' rings from:
NASA's Astronomy Picture of the Day

In 1977 during a stellar occultation experiment Uranus’ rings were accidentally discover. The discovery of Uranus’ rings happened when Uranus passed in front of a star the observers noticed that there were dips in the brightness of the star before and after Uranus’ passing. The experiment resulted in the observation of nine of Uranus’ rings. Until this point planetary rings were thought to be unique to Saturn increasing the importance of the discovery. About nine years later in 1986 the Voyager 2 spacecraft would pass by Uranus revealing two additional rings raising the ring count to eleven. On December 22, 2005 the Hubble Space Telescope would discover an additional two outer rings raising the ring count to thirteen. The brightest of Uranus’ is the epsilon ring due to it having a large composition of ice boulders that have a higher reflectivity. The other rings tend to be darker charcoal and grey colors due to consisting mainly of dust and particulate matter. The rings are believed to be fed by meteorite impacts on Uranus’ moons adding dust to the ring system which compensates for the dust and matter that would naturally slowly spiral towards Uranus.

Image of Uranus' rings from:
Space Telescope Science Institute

Uranus' Moons

Image of Uranus' five largest moons from:
The Internet Encyclopedia of Science

On William Herschel who had first discovered Uranus as a planet also made the discovery of Uranus' having moons. The first two discovered moons were named Titania and Oberon. About ninety four years later in the 1851,William Lassell would discover two more moons Ariel and Umbriel. When the first four moons were discovered they were originally given roman numeral designators, it was not until 1852 when John Herschel, William Herschel's son, named the moons after characters in works by William Shakespeare and Alexander Pope. Ninety seven years after the discovery of the third and forth moons Gerard Kuiper would discover the fifth moon Miranda. From Gerard Kuiper discovery of Miranda it would not be until the man made spacecraft Voyager 2 would pass by Uranus for ten more moons (Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda and Puck) would be discovered based off of the Voyager 2 data. There would be one more moon, Perdita, found based on the Voyager 2 data in 2001. With the exception of Perdita, there would be nine more moons, (Caliban, Sycorax, Prospero, Setebos, Stephano, Trinculo, Francisco, Margaret and Ferdinand), discovered by astronomers using ground based telescopes between 1997 and 2003. In 2003 two additional moons, Mab and Cupid, were found using the Hubble Space Telescope.

The moons Ariel, Umbriel, Belinda were all named after characters form the Alexander Pope poem "The Rape of the Lock". The remaining moons were named from plays William Shakespeare. From "A Midsummer Night's Dream" the moons Titania, Oberon and Puck received there names. Ariel, Miranda, Caliban, Sycorax, Prospero, Setebos, Stephano, Trinculo, Francisco and Ferdinand all received their names form "The Tempest". Cordelia received its name from "King Lear", Ophelia received its name from "Hamlet", Bianca received its name from "The Taming of the Shrew", Cressida received its name from "Troilus and Cressida", Desdemona received its name from "Othello", Portia received its name from "The Merchant of Venice", Rosalind received its name from "As You Like It", Margaret received its name from "Much Ado About Nothing", Perdita received its name from "The Winter's Tale", Cupid received its name from "Timon of Athens" and finally Juliet and Mab received their names from "Romeo and Juliet".

Uranus in culture

In culture Uranus the planet has little influence on culture with the exception of a hand full of fairly poor taste jokes that revolve around the miss pronunciation of Uranus as "your anus". Aside from miss pronunciations of Uranus, Uranus shares it name with a fair amount other notable Urani. Uranus or Ouranos was the Greek "Father of the Sky". Uranus also shared its name with a 1990 French film about a post World War 2 French village trying to put the war behind it. Uranus also shares it name with Operation Uranus, a Soviet operation against the Germans in World War 2. The element Uranium actually received its name from Heinrich Klaproth in an attempt to sway popularity towards renaming Uranus from "Georgium Sidus" to "Urnaus".


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