Uranus is the seventh planet from the Sun and the third largest according to diameter
(Uranus is larger in diameter but smaller in mass than Neptune). Uranus is the ancient
Greek god of the Heavens, the son and mate of Gaia the father of Cronus (which is the
Roman god Saturn).
Uranus, was the first planet discovered in modern times. It was first identified by
William Herschel but had actually been seen many times before but ignored as simply
another star. Herschel named it "the Georgium Sidus" (the Georgian Planet) in honor of
his patron, King George III of England; others called it "Herschel". The name "Uranus"
was proposed so that it would conform with the other planetary names from classical
mythology but didn't come into common use until 1850.
Most of the planets spin on an axis nearly at a right angle to the disk which the galaxy
sits in. However Uranus spins on an axis parallel to the disk. This means that Uranus’
north pole points directly at the sun, or the south pole does, depending on whether its
summer or winter. The region around the equator, which on our planet gets the most
sunlight, on Uranus will get much less . However the region around the equator of
Uranus is more hot than anywhere else. This is a mystery which astronomers have yet to
figure out.
Uranus is composed mostly of rock and random ices, with only about 15% hydrogen
and a little helium. Uranus is another of the gas planets. Its interior is in many ways
similar to the cores of Jupiter and Saturn except without the liquid metallic hydrogen.
Uranus' atmosphere is about 83% hydrogen, 15% helium and 2% methane.
Like the other gas planets, Uranus has
bands of clouds that blow around rapidly.
But they are extremely faint Uranus' blue
color is the result of absorption of red light
by methane in the upper atmosphere. There may be colored bands
like Jupiter's but they are hidden from view by the overlaying
methane layer.
Like the other gas planets, Uranus has rings. Like Jupiter's, they are very dark but like
Saturn's they are composed of larger particles ranging up to 10 meters in diameter in
addition to fine dust. The Uranian rings were the first after Saturn's to be discovered. This
was of considerable importance since we now know that rings are a common feature of
planets, not a peculiarity of Saturn alone.
Uranus is sometimes just barely visible with the unaided eye on a very
clear night; it is fairly easy to spot with binoculars (if you know exactly
where to look). A small astronomical telescope will show a small disk.
Uranus has 21 named moons and six unnamed ones. Some fun things to
know about them are that unlike all the other planets moons, Uranus’s
moons get names from the works of Shakespeare and Pope, not classical
mythology. They form 3 classes, the dark inner ones, the larger ones, and
the distant ones. Most have circular orbits around Uranus’ equator, which
therefore are at a huge angles to the disk.