Uranus | Facts, Information, History & Definition

On December 23, 1690, English astronomer John Flamsteed observed Uranus and misidentified it as a star. From the article:

"Uranus | Facts, Information, History & Definition
November 14, 2019
Uranus is the seventh planet discovered in the Solar System that also led to the discovery of the last planet, Neptune they are both referred to as ice giants. Officially recognized in 1781 after many observations in the past, it is the third largest planet of the Solar System.

Key Facts & Summary
Since ancient times it was not recognized due to its dimness and slow orbit. However, in 1781 Sir William Herschel announced its discovery being the first planet discovered with the help of a telescope.
It was given the name Uranus, after the Greek god of the sky Ouranos.
It is the only planet whose name is derived directly from a figure of Greek mythology.
The mean apparent magnitude of Uranus is 5.68 with a standard deviation of 0.17, making it near the limit of naked eye visibility.
Uranus is the seventh planet from the Sun, around 1.8 billion miles or 2.9 billion kilometers distance away.
It has the third-largest planetary radius and fourth-largest mass in the Solar System.
It has a radius of 25.362 kilometers or 15.759 miles, and has about 14.5 times the mass of Earth and four times its diameter – about 51.118 kilometers or 31.763 miles.
It is on an average distance of 19.2 AU away from the Sun and currently 18.8 AU away from Earth. Its actual distance can be checked online as Uranus is constantly tracked.
Its volume is about 63 times greater than Earth’s, which means that 63 Earths can fit inside it.
The gravity on Uranus is about 8.87 m/s² or around 86% of the surface gravity on Earth which is 9.807 m/s².
It orbits the sun quite unusually, being the only planet whose equator is nearly at a right angle to its orbit, with a tilt of 97.77 degrees. Because of this, it rotates in the opposite direction than most planets, from East to West. Venus also does this but Uranus is the only known planet to rotate on its side.
It takes Uranus 84 years to complete an orbit of the Sun, the longest from all the planets in the solar system.
It also has the shortest day. One rotation on Uranus takes about 17 hours.
Uranus has the coldest planetary atmosphere in the solar system, -224 degrees Celsius;-371 degrees Fahrenheit.
Uranus and Neptune share similar composition, both have bulk chemical compositions which differ from that of the larger gas giants Jupiter and Saturn. Because of this Uranus and Neptune are classified as ice giants rather than gas giants, for easier distinction.
Uranus has a similar atmosphere to Jupiter and Saturn in its primary composition of hydrogen and helium yet, it contains more “ices” such as water, ammonia, methane and traces of other hydrocarbons.
Though it appears featureless, without the cloud bands or storms associated with the other giant planets, it does have complex, layered cloud structure with water thought to make up the lowest clouds and methane the uppermost layer of clouds.
Through analysis, the interior of Uranus has been stated to be made up primarily of ices and rock.
Uranus has 13 known rings around it. The innermost rings are narrow and dark, and its outermost rings are brightly colored.
Like the other gas giants, it also has a magnetosphere and many moons. Until now, 27 moons have been discovered orbiting Uranus. They were named after characters from the works of William Shakespeare and Alexander Pope.
Uranus has been visited only once by a spacecraft: Voyager 2.
Though it is visible to the naked eye, Uranus escaped clear classification for decades. Generally mistaken for a star, it is speculated that Hipparchos might have recorded it first in 128 BC in his star catalogue. Later it was incorporated into Ptolemy’s Almagest.

However, the earliest definite sighting was in 1690. John Flamsteed observed it six times, cataloguing it as 34 Tauri. Later it was observed for about fourteen-times by Charles Le Monnier between 1750 and 1769. The man who finally solved this elusive object was William Herschel who observed it on 13 March 1781 with a telescope.

Although he first classified it as a comet, soon after reporting his discovery to other famous astronomers, it was concluded that in fact it was a planet. By 1783, Herschel acknowledged this and later was rewarded by the then king of England George III, on the condition that he moved to Windsor, in order for the royal family to also see it.

However, another problem was raised now, the name. It took about 70 years after the planet was discovered for astronomers to arrive at a consensus. Initially Herschel wanted to honor the king and name the new planet Georgium Sidus or “Georgian Planet.” This decision was not popular outside Britain, and alternatives were proposed such as Herschel’s own name, to even that of Neptune who wasn’t by this time discovered. Neptune was quite popular since it would have honored the British Royal Naval victories in the course of the American Revolutionary War, but it was soon dropped.

In 1782 Johann Bode proposed the name Uranus, the Latinized version of the Greek god of the sky, Ouranos. His argument was that the new planet would stand out from the others if it wasn’t following the mythology. Just as Saturn was the father of Jupiter, the new planet should be named after the father of Saturn. In 1789, an acquaintance of Bode, Martin Klaproth named his newly discovered element uranium in support of Bode’s choice. The name became universal in 1850.

In other languages such as Chinese, Japanese, Korean and Vietnamese, Uranus is translated as “sky king star.” Its official name in Thai is Dao Yurenat, in Mongolian Tengeriin Van meaning “King of the Sky” but in Hawaiian its name is Hele’ekala, a loanword for the discoverer of Uranus, Herschel."