Uranus is the seventh planet from the Sun. This planet is almost 5 times bigger than Earth and 14.5 heavier. It is about 2.9 billion km from the Sun, so far it takes 84 years to turn around the Sun, against 1 year for the Earth!
Uranus is the last planet visible to the naked eye as a pale 5.5-magnitude star. It measures 51118 km in diameter and has a beautiful blue-greenish color.
Oddly enough, while all the planets are spinning around an almost vertical axis, Uranus is inclined 98 ° to its orbit, so that it rolls more than it rotates! For 42 years one can observe his North Pole right in the center of the disc while during this time his South Pole never sees the Sun and must face a winter with temperatures of -223 ° C!
Like Jupiter, the atmosphere of Uranus is composed of hydrogen, helium and some methane. If its atmosphere is gaseous, its core is solid and has a temperature of 10000 ° C.
Uranus is a calm planet. Atmospheric cloud layers have been discovered in the atmosphere. Much paler than those of Jupiter and Saturn, they move from east to west at a speed not exceeding 576 km / h while the average wind speed is of the order of 360 km / h.
In 1977, astronomers discovered rings around Uranus. There are now 13 of them and they look like Saturn’s, but they are much paler. The brightest ring is called espilon. Its width varies between 20 and 100 km for a maximum thickness of 150 m.
Uranus being a big planet, it surrounds itself with 27 satellites of which 5 are visible in an amateur telescope like small very pale points. All look like the Moon and measure between a few tens and a few hundred kilometers in diameter.