Uranus It is the seventh planet from the Sun, the third largest and the fourth most massive in the Solar System. It is also the first that was discovered thanks to the telescope: Herschel found it in 1781.
He received the name of the Greek god of heaven, Uranus, what does it mean firmament. This titan was the son and husband of Gea, Mother Earth, who had conceived it for herself. From them descend most of the Greek gods. Uranus and Gea were the parents of Cronus (Saturn) and grandparents of Zeus (Jupiter).
Sometimes the planets Uranus and Neptune are classified as frozen giants, since its composition is similar and somewhat different from the other two gas giants, Jupiter and Saturn. The atmosphere of Uranus is formed by hydrogen, methane and other hydrocarbons. Methane absorbs red light, so it reflects blue and green tones.
The following table shows Uranus data compared to Earth:
|Basic data||Uranus||The earth|
|Size: equatorial radius||25,362 km.||6,378 km.|
|Average distance to the Sun||2,870,972,200 km.||149,600,000 km.|
|Day: period of rotation on the axis||17.9 hours||23.93 hours|
|Year: orbit around the Sun||84.01 years||1 year|
|Average surface temperature||-197 º C||15 º C|
|Surface gravity in the equator||7.77 m / s2||9.78 m / s2|
Its distance from the Sun is twice that of Saturn. It is so far away that, from Uranus, the Sun looks like another star. Although, much brighter than the others. Its equatorial radius is about four times that of Earth.
Uranus is tilted 98 degrees, so that the equator forms almost a right angle to the path of the orbit. This makes in some moments the hottest part, facing the Sun, is one of the poles.
The surprising inclination of Uranus causes a curious effect: its magnetic field tilts 60 degrees in relation to the axis and the magnetic tail is shaped like a ringlets, due to the rotation of the planet.
Uranus, discovered by Sir William Herschel on March 13, 1781, it is visible without a telescope. Surely someone had seen it before, but the huge distance makes it shine very little and move slowly. In addition, in the sky there are more than 5,000 stars brighter than him.
Like the other giant planets of the Solar System, Uranus also has a ring system. They are very narrow and consist of dark particles.
In 1977 the first 9 were discovered uranus rings. In 1986, the Voyager ship visit allowed measuring and photographing the rings, and discovering two new ones. So far 13 rings have been discovered.
The rings of Uranus are different from those of Jupiter and Saturn. Outside, Épsilon is formed by large ice rocks and has a gray color. It seems that there are other rings, or fragments, not very wide, of about 50 meters.
It is believed that these rings did not form at the same time as the planet; on the contrary, they are quite recent and could have been part of satellites torn apart by impacts. Only a few particles were retained in the stable areas that the current Uranus rings occupy.
• Biography of William Herschel, the astronomer who discovered Uranus
• Why the inclination of the Uranus axis?
• When Uranus was simply called "George"
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