How would you describe the surface, atmosphere and interior of Uranus. Who discovered Uranus and what are some the NASA missions?© BrainMass Inc. brainmass.com December 24, 2021, 9:13 pm ad1c9bdddf
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Knowledge about the internal structure of the planet Uranus has been gained from information gathered by a recent deep space probe flyby (Voyager 2) and inferred from the planet's radius, mass, period of rotation, the shape of its gravitational field and the spectral information gathered. More importantly hydrogen, helium, water, methane and ammonia have been found to be the main constituents of the planet and it is from study of these compounds and elements at high pressure that properties of the internal structure can be inferred. Its internal structure is similar to that of Neptune except for the fact that it is less active in terms of atmospheric dynamics and interior heat flow.
It is thought that 20% of the total radius of the planet constitutes the rocky core; this being roughly 0.5 Earth masses. The icy mantle is then thought to extend from a point at roughly 20% the total planet radius to 80% the planet radius. Finally the atmosphere which we observe extends from 80% of the planets radius to the boundary with space.
The atmosphere of Uranus is chiefly composed of gases consisting of molecular hydrogen, helium, methane and other trace hydrocarbons, with a small percent of ices of water and ammonia. This atmosphere is roughly the mass of one to two Earths masses. Below this region Uranus appears to be composed of a mantle rich in water, methane, ammonia, and other elements. These elements are under high temperatures and pressures deep within the planet. The mantle is equivalent to 10 to 15 earth masses. Uranus's core is composed of rock (silicates and metals) and ice, and is likely no more than one Earth mass, probably around 0.5 Earth mass.
Uranus possesses the coldest planetary atmosphere in the Solar System where average temperatures down to -224 DEG C have been determined. A complex cloud structure exists with water clouds forming at lower layers and with methane clouds thought to form the uppermost cloud layers. The atmosphere can be divided into 3 main regions the lowest layer being the troposphere extending to 50km, then the stratosphere extending from 50 to 4000 km, then the top layer, the thermosphere extending from 4000km up to 50,000 km above the planetary surface. Clouds of Methane (~2.3%) give rise to the predominant Green-Blue (Cyan) coloration of the planet as observed; Methane being a very strong absorber of red and IR light.
The planet is roughly 4 Earth radii in extent, slightly physically larger than Neptune but less massive. After Saturn, Uranus is in fact the second least dense planet in the Solar System which leads Astronomers to believe that the planet is chiefly composed of water, ammonia and methane ices.
Uranus was first discovered in 1781 by the Astronomer William Herschel who originally named the planet "Georges Star" in honour of the then King of England, King George III.
Nasa's Voyager2 space probe has been the only probe to have flown by Uranus to date (Ref: http://solarsystem.nasa.gov/missions/profile.cfm?Sort=Target&Target=Uranus&MCode=Voyager_2)
identifying some remarkable new facts including the existence of a thin ring system and a non-dipole, non axial symmetric magnetic field.