The planet Uranus is the seventh planet in our solar system, measured
in distance from the sun. It is one of the gas giants in the outer parts of
our solar system, residing at a mean distance of 2.87 ยท 109 km,
with a period of revolution of little over 84 years. Uranus was discovered
by German/British astronomer Sir William Herschel in 1781. It
was the first new planet discovered since Babylonian astronomy and it
was later discovered that the planet had been observed and recorded as a star over
20 times before it was recognized as a planet. Herschel also discovered the
planet's two largest moons, Titania and Oberon.
The planet's atmosphere consists mostly of hydrogen, helium and
methane. In the center of the planet, these gases and others probably exist
together with minerals and metal particles. As the distance from the center
grows, they become solid, then fluids and then gaseous. Because the methane in
the atmosphere, the planet looks bluish green in color; methane absorbs parts of
the red spectrum. The planet has not apparent visual surface attributes, and
there are not weather or other wind related patterns like on Jupiter and
Saturn, even though strong winds have been observed.
An interesting feature about Uranus is its axis of rotation. The
planet is tilted at 98 degrees, which means that there's only an 8 degree angle
between the axis of rotation and the plane of rotation around the sun. The planet
appears to be rolling around the sun in its orbit. Uranus also has a short
period of rotation, just above 17 hours, which has flattened the planet
considerably, making it more elliptical than most planets. The equatorial
circumference is about 2.4 % greater than the polar circumference. Also, the
angle between the magnetic axis and the axis of rotation is almost 57 degrees,
compared to Earth's 11 degrees. The source of the magnetic field is unknown,
since there are no traces of electrically conductive oceans of molten core -
which is the case of Earth.
Uranus has 22 known moons, all of which are named after characters in Shakespeare
dramas. The planet has at least 22 moons and thirteen thin rings inside the moon
system.