Uranus is the seventh planet from the Sun. It is named after the Greek god Uranus, who was a god of sky.
German-born British astronomer and composer William Herschel discovered Uranus in 1781 while in the garden of his house in Bath, Somerset, England, thinking it was a comet.
Uranium was discovered eight years later by the German chemist Martin Heinrich Klaproth and he named the element after the newly discovered planet.
In 1977 Astronomers using NASA's Kuiper Airborne Observatory, an observatory aboard a highly modified jet aircraft, discovered a faint planetary ring system around Uranus.
In 1986 the Voyager space probe reached Uranus, detecting 11 rings in all, and finding 10 small moons in addition to the five visible from Earth. It is the only space probe that tried to investigate the planet from a short distance.
Uranus has a diameter of 51,000 km, 31,700 miles and a mass roughly 14.5 times that of Earth. 63 Earths could fit inside of Uranus.
It orbits the sun every 84 years at an average distance of 2,817 million km (1,780 million miles). The intensity of sunlight on Uranus is about 1/400 that on Earth.
It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K (−224 °C; −371 °F).
Uranus only has two seasons - summer and winter. Each lasts 42 Earth years.
There are violent storms. Wind speeds can reach 250 metres per second (900 km/h; 560 mph).
Uranus has a small rocky core (about 55% the mass of Earth) overlain by ice with a deep atmosphere containing mainly hydrogen, helium plus some methane which gives the planet a greenish tinge.
Uranus is covered in blue clouds. The top clouds are made of methane and the lower clouds are thought to be frozen water.
The rings are charcoal black, and are probably debris of former "moonlets" that have broken up.
Thirteen distinct rings are known which is far fewer than the rings of Saturn but more than those around Jupiter and Neptune.
Uranus smells like flatulence because its atmosphere consists largely of hydrogen sulfide.
The spin axis of Uranus is tilted at 98 degrees, so that at times it's poles point towards the Sun, giving extreme seasons.
Uranus has a peculiar magnetic field, whose axis is tilted at 60° to its axis of spin, and is displaced about one third of the way from the planet's center to its surface. Because the magnetic field is so off-kilter with its rotational axis that magnetic lines will snap apart and reconnect as it rotates. According to one astronomer, "Uranus is a geometric mess."
Observations of the magnetic field show that the solid body of the planet rotates every 17.3 hours. The rotation rate of the atmosphere varies with latitude, from about 16 hours in mid southern latitudes to longer than 17 hours at the equator.
Uranus has 27 known moons. 24 are named after characters from the works of Shakespeare and three from Alexander Pope's. The largest moon, Titania, has a diameter of 1,610 km (1,000 miles).
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| Uranus pictured as a featureless disc by Voyager 2 in 1986 |
German-born British astronomer and composer William Herschel discovered Uranus in 1781 while in the garden of his house in Bath, Somerset, England, thinking it was a comet.
Uranium was discovered eight years later by the German chemist Martin Heinrich Klaproth and he named the element after the newly discovered planet.
In 1977 Astronomers using NASA's Kuiper Airborne Observatory, an observatory aboard a highly modified jet aircraft, discovered a faint planetary ring system around Uranus.
In 1986 the Voyager space probe reached Uranus, detecting 11 rings in all, and finding 10 small moons in addition to the five visible from Earth. It is the only space probe that tried to investigate the planet from a short distance.
Uranus has a diameter of 51,000 km, 31,700 miles and a mass roughly 14.5 times that of Earth. 63 Earths could fit inside of Uranus.
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| Size comparison of Earth and Uranus |
It orbits the sun every 84 years at an average distance of 2,817 million km (1,780 million miles). The intensity of sunlight on Uranus is about 1/400 that on Earth.
It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K (−224 °C; −371 °F).
Uranus only has two seasons - summer and winter. Each lasts 42 Earth years.
There are violent storms. Wind speeds can reach 250 metres per second (900 km/h; 560 mph).
Uranus has a small rocky core (about 55% the mass of Earth) overlain by ice with a deep atmosphere containing mainly hydrogen, helium plus some methane which gives the planet a greenish tinge.
Uranus is covered in blue clouds. The top clouds are made of methane and the lower clouds are thought to be frozen water.
The rings are charcoal black, and are probably debris of former "moonlets" that have broken up.
Thirteen distinct rings are known which is far fewer than the rings of Saturn but more than those around Jupiter and Neptune.
Uranus smells like flatulence because its atmosphere consists largely of hydrogen sulfide.
The spin axis of Uranus is tilted at 98 degrees, so that at times it's poles point towards the Sun, giving extreme seasons.
Uranus has a peculiar magnetic field, whose axis is tilted at 60° to its axis of spin, and is displaced about one third of the way from the planet's center to its surface. Because the magnetic field is so off-kilter with its rotational axis that magnetic lines will snap apart and reconnect as it rotates. According to one astronomer, "Uranus is a geometric mess."
Observations of the magnetic field show that the solid body of the planet rotates every 17.3 hours. The rotation rate of the atmosphere varies with latitude, from about 16 hours in mid southern latitudes to longer than 17 hours at the equator.
Uranus has 27 known moons. 24 are named after characters from the works of Shakespeare and three from Alexander Pope's. The largest moon, Titania, has a diameter of 1,610 km (1,000 miles).
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