Uranus
Uranus is the third largest planet in the Solar System having a diameter of 51,000 kilometers. It is the seventh planet from the Sun. Uranus was named after the Greek-Roman God who was the father of Saturn. It consists of solid rocky core surrounded by dense mixture of icy and gaseous water, methane and ammonia. An atmosphere of hydrogen, helium and methane give this planet a bluish green appearence. A spectacular feature of Uranus is that its axis tilts at an angle of 97.9°, so that it revolves round the Sun on its sides like a huge rolling ball, Unlike other planets (except Venus) Uranus spins in the opposite direction Uranus takes 17 hours and 8 minutes to spin on its axis and about 84 years to revolve round the sun. A system of 11 narrow rings formed from scattered rocks and dust particles are found surrounding the planet. The rings cannot be detected clearly because they are made up of the darkest particles. Uranus has 18 known satellites and most of them are named after Shakespearean characters. The inner ten satellites are dark and small having less than 160 kilometres in diameter. The outer ve are larger in diameter between 470 and 1,600 kilometres. Miranda, Ariel, Titania, Umbriel and Oberon are the outer satellites. The surface features of these five satellites vary widely. Oberon has cratered surface like the moon whereas Miranda is twisted and jumbled with large ridges and cliffs of about 20 kilometres in height, which breaks up to form huge craters. Uranus is the most featureless planet in the Solar System.
Rings of Uranus
The rings of Uranus are formed of the darkest particles. So they cannot be detected clearly.
Probe to Uranus
During January 1986 Voyager-2 of United States passed 81000 kilometres of Uranus and collected many details including a magnetic field encircling the planet. It also discovered 10 small satellites inside the orbit of Miranda, one of the large satellites of Uranus.
Uranus
Distance from the sun in km.: 2875 million Diameter at equator in km.: 51,118
Mass with respect to the earth: 14.54 (earth=1)
Gravity with respect to the earth: 0.91
Period of revolution: 84 earth years
Period of rotation: 17 hours and 8 minutes
Density (g/cm³): 1.27
Temperature: -216° C
Satellites: 18
