Uranus

The Magician

  Uranus is the ancient Greek deity of the Heavens, the earliest supreme god. Uranus was the son and mate of Gaia the father of Cronus, Saturn, and of the Cyclopes and Titans (predecessors of the Olympian gods).

  Uranus is the seventh planet in order of distance from the Sun and the third largest. Uranus is larger in diameter the Neptune but smaller in mass.

  Uranus, the first planet to be discoverd in modern times, was discovered by William Herschel while systematicly searching in the sky with his telescope on March 13, 1781. It had actually been seen many times before but ignored as simply another star. The earliest recorded sighting was in the year 1690 when John Flamsteed cataloged it as 34 Tauri. But Herschel named it as "Georgium Sidus" in honour of his patron, the infamous King Geroge III of England; others called it "Herschel". The name Uranus was first proposed by Bode in conformity with the other planetary names form classical mythology but it didnīt come in common use until 1850.

  The only spacecraft to visit Uranus is Voyager 2 on January the 24th in the year 1986.

  Most of the planets spin on an axis nearly perpendicular to the plane of the ecliptic but Uranusī axis is almost parallel to the ecliptic. At the time of Voyager 2īs passage, Uranusī south polar regions receive more energy input from the Sun than do its equatorial regions. Uranus is nevertheless hotter at its equator than at its poles. The mechanism underlying this is unknown.

  There is actually an ongoing battle over which Uranusī poles is its north pole! Either its axial inclination is a bit over 90 degrees and its rotation is direct, or it is a bit less than 90 degrees and the rotation is retrograde. The problem is that you need to draw a dividing line "somewhere" because in a case like Venus there is a little dispute that the rotation is indeed retrograde.

  Uranus is composed of rock and various ices, with only about 15% hydrogen and little helium. Uranus and neptune are in many ways similar to the cores of Jupiter and Saturn minus the massive liquid metallic hydrogen envelope. It appears that Uranus does not have a rocky core like Jupiter and Saturn but rather than its material is more or less uniformly distributed.

  Uranusī atmosphere is about 83% hydrogen, 15% helium and 2% methane.

  Uranus, like the other gas planets, has bands of clouds that blow around rapidly. They are extremely faint, visible only with radical image enchancement of the Voyager 2 pictures. Recent observations with the Hubble Space Telescope show larger and more pronounced streaks. Further observations show even more activity. Uranus is no longer the bland boring planet that Voyager saw! It now seems clear that the differances due to seasonal effects since the Sun is now at lower Uranian latitude which may cause more pronounced day/night weather effects. By 2007 the Sun will be directly over Uranusīs equator.

  The blue colour of Uranus is the result of absorption of red light by methane in the upper atmosphere. There may be colored bands like Jupiterīs but they are hidden from view by the overlaying methane layer.

  Uranus has rings like the other gas planets. They are very dark but like Saturnīs composed of fairly large particles ranging up to 10 meters in diameter in addition to fine dust. There are 11 known rings, which are all very faint, the brightest is known as the Epsilon ring. Uranusī rings were the first to be discoverd after Saturnīs. This was considerable importance since we now know that rings are common feature of planets, not a peculiarity of Saturn alone.

  Voyager two discovered 10 small moons in addition to the 5 large ones already known. It is likely that there are several others more tiny satellites within the tiny rings.

  The magnetic field of Uranus is odd in that it is not centerd on the center of the planet and is tilted almost 60 degrees with respect to the axis of rotation. It is probably generated by motion at realtively shallow depths within Uranus.

  The planet is sometimes just barely visible with the naked eye on a very clear night; it is fairly easy to spot with bonoculars, if you know where to look,. A small telescope will show small disk.

  Uranus has 15 moons plus 5 recently discovered ones which have yet not been given official names. In thus has the most known moons of any planet. The Uranian moons have names from the writings of Shakespeare and the Pope, unlike other bodies in the solar system which have names from classical mythology.

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