Uranus

Uranus is unique among the planets in having its rotation axis tilted close to the plane of the ecliptic. The north pole of Uranus is inclined 98° to the ecliptic plane (8° south of the plane), and the seasons on Uranus average 21 terrestrial years in length. The effect of this geometry on the large-scale circulation of the Uranium atmosphere is not fully understood, but it is expected to be significant. 

The radio emissions from Uranus arise from sufficient depths that collision-induced absorption by hydrogen is an important source of opacity at millimeter wavelengths. Ammonia is severely depleted in Uranus atmosphere, at least at pressure levels less than 25 bar. Since, based upon planet formation theories, nitrogen must be present in at least solar proportions, it is believed that ammonia gas is abundant at deeper levels, but reacts with H2S to form a cloud of NH4SH. If indeed this process accounts for the observed depletion in NH3, hydrogen sulfide should be enriched in Uranus atmosphere by about an order of magnitude over solar S. Such an abundance of H2S itself will contribute to the radio opacity in Uranus atmosphere and actually help reconcile observed spectra with models. 

Another interesting aspect of the radio emission from Uranus is that its total intensity varies slowly over time. With the help of interferometric (VLA) observations, it is well established that the Uranus pole is warmer than its equator. This will certainly lead to time variations during Uranus orbit around the Sun. It is not known, however, whether this indeed fully explains the observed time variability. 

The Voyager spacecraft detected a wide variety of radio emissions from Uranus during its encounter in January 

The mass of Uranus is 14.5 times that of the Earth. Uranus consists of three layers  

In 1977, astronomers discovered that Uranus is surrounded by a system of rings similar to those of Saturn. They lie in a concentric pattern around the planet s equator. Uranus s axis of rotation is parallel with its plane of revolution, rather than perpendicular to it, like Earth s. In other words, instead of spinning like a top on its path around the Sun, as Earth does, Uranus rolls along it like a barrel. Consequently, the planet s rings form a bull s-eye pattern pointing at the Sun. 

Source Linda J. Spilker, ed. Passage to a Ringed World The Cassini-Huygens Mission to Saturn and Titan. NASA Special Publication SP-533. Washington, D.C. National Aeronautics and Space Administration, October 1997, Chapter 3. 

Also available online at http //saturn.jpl-nasa.gov/gallery/products/pdfs/ chapter3.pdf. 

Apart from its most general features, the physical and chemical characteristics of Uranus were largely unknown to astronomers prior to the Voyager 2 flyby in 1981. That mission, however, provided a host of new data about the planet, its ring system, and its moons. For example, Voyager reported that the temperature of the planet at both poles is approximately the same, about 58 K (—215°C), in spite of the fact that one pole always points toward the Sun and the other pole 

As they do with other planets, scientists base their hypotheses of the structure of Uranus s interior on observed physical properties. According to one popular model, the planet consists of a large core composed primarily of silicon and oxygen that is surrounded by first, a layer consisting of water ice and rock then, by an envelope of liquid hydrogen and, finally, by an outermost envelope made of gaseous hydrogen, helium, methane, ammonia, and water. 

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Nellis W J, Flamilton D C, Flolmes N C, Radousky FI B, Ree F FI, Mitohell A C and Niool M 1988 The nature of the interior of Uranus based on studies of planetary ioes at high dynamio pressure Science 240 779... 

Planet Uranus) Yellow-colored glass, containing more than 1% uranium oxide and dating back to 79 A.D., has been found near Naples, Italy. Klaproth recognized an unknown element in pitchblende and attempted to isolate the metal in 1789. 

Alkanes have the general molecular formula C H2 +2 The srmplest one methane (CH4) rs also the most abundant Large amounts are present rn our atmosphere rn the ground and rn the oceans Methane has been found on Juprter Saturn Uranus Neptune and Pluto and even on Halley s Comet... 

Diacetylene (HC=C—C=CH) has been identified as a component of the hydrocarbon rich atmospheres of Uranus Neptune and Pluto It is also present m the atmospheres of Titan and Triton satellites of Saturn and Neptune respectively... 

Uranium [7440-61-17 is a naturally occurring radioactive element with atomic number 92 and atomic mass 238.03. Uranium was discovered in a pitchblende [1317-75-5] specimen ia 1789 by M. H. Klaproth (1) who named the element uranit after the planet Uranus, which had been recendy discovered. For 50 years the material discovered by Klaproth was thought to be metallic uranium. Pnligot showed that the uranit discovered by Klaproth was really uranium dioxide [1344-57-6] UO2, and obtained the tme elemental uranium as a black powder in 1841 by reduction of UCl [10026-10-5] with potassium (2). 

In 1789 M. H. Klaproth examined pitchblende, thought at the time to be a mixed oxide ore of zinc, iron and tungsten, and showed that it contained a new element which he named uranium after the recendy discovered planet, Uranus. Then in 1828 J. J. Berzelius obtained an oxide, from a Norwegian ore now known as thorite he named this thoria after the Scandinavian god of war and, by reduction of its tetrachloride with potassium, isolated the metal thorium. The same method was subsequendy used in 1841 by B. Peligot to effect the first preparation of metallic uranium. 

As it was the next element after uranium in the now extended periodic table it was named neptunium after Neptune, which is the next planet beyond Uranus. 

Uranus Stainless Steels for Severe Corrosion Conditions, CAFL, France... 

Our solar system consists of the Sun, the planets and their moon satellites, asteroids (small planets), comets, and meteorites. The planets are generally divided into two categories Earth-like (terrestrial) planets—Mercury, Venus, Earth, and Mars and Giant planets—Jupiter, Saturn, Uranus, and Neptune. Little is known about Pluto, the most remote planet from Earth. 

Unsaturated, hydrocarbons, 342 Uranium compounds, 223 electron configuration, 415 oxidation number, 414 preparation, 35 Uranium hexafluoride, 35 Uranus, data on, 444 Urea, 434... 

Effects of condensation are also seen in the bulk compositions of the planets and their satellites. The outer planets, Uranus and Neptune, have overall densities consistent with their formation from icy and stony solids. The satellites of Uranus have typical densities of 1.3g/cm which would tend to indicate a large ice com-... 

Name named after the planet Uranus, which was discovered as a new planet shortly before (1781) when 0. Hahn split the uranium atom in 1939, we entered the atomic age... 

Name named after Neptune (the planet after Uranus)... 

The gas giant planets Jupiter, Saturn, Uranus and Neptune. The planet Pluto has a status of its own, and has recently been renamed a dwarf planet. 

Although Uranus and Neptune also belong to the group of gas giant planets, they are constructed differently from Jupiter and Saturn ... 

Uranus The temperature in the Uranus atmosphere, which consists of molecular hydrogen containing around 12% helium, is close to 60 K. A methane cloud layer has been detected in the lower layers of this atmosphere. The planet is surrounded by a magnetosphere which extends into space for about ten times the diameter of Uranus. The planet has 27 moons of various sizes and is surrounded by a ring system which consists of thin dark rings. The planet is unusual in two respects its tilted axis and retrograde rotation. 

The latter group was probably responsible for the early bombardment of the protoplanets. Delsemme believes that the cometary nuclei of the members of the Jupiter family never experienced temperatures greater than 225 K. The values suggested for the others are Saturn family, 150K Uranus family, 75 K Neptune family, 50 K. During many million years, these comets got mixed together in the Oort cloud (which has a diameter of around 50,000 AU). 

The formation of the planets around the proto-sun initially started as a simple accretion process, aggregating small particles to form larger particles. This process was common to all planets, even the gas giants Jupiter and Saturn and to a lesser extent Neptune and Uranus. The planetesimals form at different rates and as soon as Jupiter and Saturn had reached a critical mass they were able to trap large amounts of hydrogen and helium from the solar nebula. The centres of Jupiter... 

The density estimates in Table 7.1 show a distinction between the structures of the planets, with Mercury, Venus, Earth and Mars all having mean densities consistent with a rocky internal structure. The Earth-like nature of their composition, orbital periods and distance from the Sun enable these to be classified as the terrestrial planets. Jupiter, Saturn and Uranus have very low densities and are simple gas giants, perhaps with a very small rocky core. Neptune and Pluto clearly contain more dense materials, perhaps a mixture of gas, rock and ice. 

Equation of State and Electrical Conductivity of Synthetic Uranus, ... 

Uranium (U, [Rn]5/36t/1752), name and symbol after the planet Uranus. Discovered (1789) by Martin J. Klaproth, the metal was isolated (1841) by Eugene M. Peligot. Silvery metal. 

Figure 3. The regions of pressure and temperature accessible by joining static compression methods to heating and cooling techniques are compared to the Earth geotherm and to Jupiter and Uranus isentropes.

Neptunium - the atomic niunber is 93 and the chemical symbol is Np. The name derives from the planet Neptune (the Roman god of the sea), since it is the next outer-most planet beyond the planet uranus in the solar system and this element is the next one beyond uranium in the periodic table.lt was first synthesized by Edwin M. McMillan and Philip H. Abelson in 1940 via the nuclear reaction n, y) U P = p. The longest half-life associated with this mistable... 

Uranium - the atomic number is 92 and the chemical symbol is U. The name derives from the planet Uranus, which in Roman mythology was Father Heaven . The German chemist Martin-Heinrich Klaproth discovered the element in 1789, following the German/English astronomer William Hershel s discovery of the planet in 1781. The metal was first isolated by the French chemist Eugene-Melchior Peligot in 1841. 

At the end of the eighteenth century, scientists thought that pitchblende was a mixture of iron and zinc compounds. In 1789 Martin Heinrich Klaproth (1743—1817) discovered a new metallic element in a sample of pitchblende, which he named uranus after the recently discovered planet. Although what he actually discovered was the compound uranous oxide (UOj), it was adequate to establish him as the discoverer of uranium. For almost a century, scientists believed that the compound uranous oxide (UO ) was the elemental metal uranium. In 1841 Eugene-Melchoir Pefigot (1811—1890) finally isolated the metal uranium from its compound. Even so, no one knew that both the compounds and metal of uranium were radioactive until 1896, when Henri Becquerel (1852—1908) mistakenly placed apiece of potassium... 

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