According to Space.com, scientists are contemplating sending a robotic probe to Uranus, the seventh planet from the sun, described as an "ice giant." Uranus has only been visited briefly by the Voyage 2 flyby probe in 1986.
* The proposed mission, which would orbit Uranus much as Cassini currently orbits Saturn and Galileo once orbited Jupiter, would be launched sometime in the 2020s, when the planet is in the best position to be accessed from Earth. The mission, which would comprise of an orbiter and a probe that would penetrate Uranus' atmosphere, would cost somewhere between $1.5 billion and $2.7 billion dollars.
* Voyager 2 flew within 50,600 miles of Uranus. It managed to image the planet, its rings, and five of its largest moons. It discovered 10 previously unknown moons. Voyager 2 also discovered that Uranus' rotation was 17 hours, 14 minutes, that its magnetic field was "large and unusual," and that the temperature of its equatorial region, which receives less sunlight than the polar region pointed at the sun, nevertheless has about the same temperature.
* Uranus was discovered to be a planet by the British astronomer William Herschel on March 13, 1781. Herschel named the planet "Georgium Sidus" after his royal patron, King George III. Eventually the planet was named Uranus by 1850 in conformity to naming planets after gods of Roman mythology.
* Uranus appears to have been hit by multiple strikes so that its axes, rather than its equator, are parallel to the plane of the elliptic.
* Unlike Jupiter and Saturn, Uranus is composed primarily of rock and ices, primarily water, ammonia, carbon dioxide, and methane. Its atmosphere is mainly composed of hydrogen, with some helium and methane.
* Uranus has 13 known rings, common to all of the other outer planets.
* According to 1-2-3problemsolved.com, Uranus' magnetic field is "odd" in that it is not on the center of the planet and is tilted 60 degrees with respect of the axis of rotation.
* Uranus is 2,870,990,000 kilometers from the sun and takes 84 years to revolve around the sun. Uranus is 51,118 in diameter.
* There are 27 moons in orbit around Uranus, only five of which are much larger than the average asteroid. The moons of Uranus are named after characters in Shakespeare's plays and the poems of Alexander Pope. The five largest moons are Miranda, Ariel, Umbriel, Titania, and Oberon.
* Questions that the proposed probe to Uranus would try to answer include why does it radiate more heat than do Jupiter and Saturn, why is it so tilted in respect to the plane of the elliptic, and why does its atmosphere have less hydrogen and helium than do Jupiter and Saturn. An orbiting probe around Uranus would also examine its weather patterns.
Mark R. Whittington is the author of
Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post , USA Today, the L.A. Times and The Weekly Standard.
