Uranus appears to be a blue-green disk when viewed at through a large telescope. With the naked eye, it appears to look like a star in the sky. In pictures it looks like a large, light blue ball. Uranus is the farthest planet that can be seen with the naked eye. It is the seventh planet from the sun in the solar system. In addition, it is the third largest planet in the solar system. Uranus is the first planet discovered by telescope.
Uranus was discovered in 1781 by a musician who eventually became an astronomer. His name was William Herschel. He found it while viewing through a homemade telescope. Herschel thought it was a comet. Eventually it was found to be a planet. The planet was named Uranus after the Roman and Greek mythological gods.
Most of the information known about Uranus was discovered by the Voyager 2 mission and the Hubble Space Telescope. Uranus is about 1.78 billion miles from the Sun. The diameter of Uranus is around 31,800 miles which is at least four times larger than Earth's diameter. In addition, the mass of Uranus is least fourteen times larger than Earth's mass. Hydrogen makes up the majority of the atmosphere of Uranus. Uranus revolves in its orbit around the sun in 84 Earth years. It rotates in its axis in 18 Earth hours. Uranus is a very cold planet. Its average temperature is around -355 degrees Fahrenheit; however, it does have a very hot ocean located on it. The ocean's temperature is 4,200 degrees Fahrenheit. It is believed that the water does not evaporate because of deep pressure in Uranus. Uranus appears to be tipped over. Some believe that it appears tipped over because it was hit by some large object (possibly a planet) that knocked it over. It is the only known planet in the solar system that does appear to be tipped over. Some also believe that some of the debris from the hit helped develop rings around the planet.
Uranus has at least 13 rings and 27 natural satellites (moons). The rings appear to be dark and the majority of the rings are thin. Some believe that the rings are made from crushed moons, debris from other planets, and ice. Some of the outer rings have Greek letter names such as Alpha, Beta, Eta, Gamma, and Delta. Epsilon, the farthest known ring from Uranus, has at least two shepherd satellites (moons that orbit close to rings). The moons of Uranus are setup in a system. There are at least ten smaller moons that have dark surfaces and are closer to Uranus. In addition, there are five larger, brighter moons that are farther away from Uranus but were discovered much earlier than the ten smaller moons. The moons of Uranus are named after characters from Shakespeare plays and Alexander Pope's writings. The largest moon is named Titania; the smallest moon, Trinculo.
"Uranus." The World Book Encyclopedia. 2009.20:217-219.