Astronomy Uranus Was the First Planet Discovered Essay

Astronomy

Uranus

Uranus was the first planet discovered in contemporary times. It was discovered in 1781 by William Herschel while he was searching the sky with his telescope. It had actually been seen many times before but ignored as simply being another star. "In the beginning Herschel named it "the Georgium Sidus" (the Georgian Planet) in honor King George III of England. Others called it "Herschel." The name "Uranus" was first proposed by Bode in conformity with the other planetary names from classical mythology but didn't come into common use until 1850" (Uranus, 2011).

The only spacecraft to ever visit Uranus was Voyager 2 in 1986. Uranus is different in that most of the planets spin on an axis almost perpendicular to the plane of the ecliptic but Uranus' axis is almost parallel to the ecliptic. At the time of Voyager 2's passage, Uranus' South Pole was pointed almost directly towards the Sun. This results in the odd fact that Uranus' Polar Regions receive more energy input from the Sun than do its equatorial regions. Uranus is nonetheless hotter at its equator than at its poles and the reason for this is currently unknown (Uranus, 2011).There has been a continuing dispute over which of Uranus' poles is its north pole. "Either its axial inclination is a bit over 90 degrees and its rotation is direct, or it's a bit less than 90 degrees and the rotation is retrograde. The issue is that one needs to draw a dividing line somewhere, because in a case like Venus there is little argument that the rotation is indeed not a direct rotation with an inclination of nearly 180 degrees" (Uranus, 2011).

Uranus is the seventh planet from the Sun and the third largest in diameter. It is made up mainly of rock and various ices, with only about fifteen percent hydrogen and very little helium. This is in direct contrast to Jupiter and Saturn which are made up mostly of hydrogen. Uranus and Neptune are in a lot of ways similar to the cores of Jupiter and Saturn less the massive liquid metallic hydrogen envelope. It appears that Uranus does not have a rocky core like Jupiter and Saturn but rather that….....