Uranus was discovered by W. Herschel in 1781. In 1986 Uranus was explored for the first time up-close by Voyager 2. It is a major planet with a diameter four times that of our Earth. Uranusí atmosphere is about 11,000 km deep containing 83% hydrogen, 15% helium, 2% methane and small amounts of acetylene and other hydrocarbons. Methane in the upper atmosphere absorbs red light, giving Uranus its blue-green color. The temperature located in the upper cloud layer is about -210 C.
The rotation of the planet is quite extraordinary. Uranusí rotational axis is practically in the orbital plane. The planet's rotation period is approximately 17 hours. Even more amazingly, Uranusí magnetic axis is inclined at 55 degrees to its rotational axis. The planet has a strong magneic field as well.
Uranusí Rings were discovered in 1977 during observation of the "disappearance" of a star by Uranusí disc. It was discovered that the star's brightness changed after and before the "disappearance". Futher observations of this led to the discovery of nine narrow rings that orbit the planet at a distance of 42,000 to 51,000 km. Voyager 2 also discovered additional rings.
Uranus has nothing like the colourful bands of Jupiter. Uranus has a haze of methane crystals that blocks what lies beneath. Voyager 2 in 1986 captured images of some rare clouds, elevated by the eddies below. Sometimes such pictures are captured by the Hubble telescope.
The planet's core is a rocky structure around the size of Earthís core.The core is surrounded by a much greater mass of slush-containing mostly water mixed with methane-thousands of km deep. Overlying all of this is a thick atmosphere of 7/8 hydrogen and 1/8 helium.
|The Moons of Uranus:|
Moons of Uranus