Saturn composition

In the region of the terrestrial planets, there may have been several thousand planetesimals of up to several hundred kilometres in diameter. During about ten million years, these united to form the four planets—Mercury, Venus, Earth and Mars—which are close to the sun. Far outside the orbit of the planet Mars, the heavier planets were formed, in particular Jupiter and Saturn, the huge masses of which attracted all the hydrogen and helium around them. Apart from their cores, these planets have a similar composition to that of the sun. Between the planets Mars and Jupiter, there is a large zone which should really contain another planet. It... 

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. 

Thermoplastic composites for the vertical body panels of General Motors Saturne (1000 vehicles per day). 

It is not therefore to the planets that we should associate the elements iron with Mars, lead with Saturn, mercury with Mercury. It is indeed the stars that have nurtured them. Some stars make carbon, others gold. Thermonuclear combustion modifies the composition of the hottest regions within stars. Each star is responsible for the confection and distribution of a particular batch of atoms, apart from hydrogen and a large part of the helium in the Universe which were synthesised in the Big Bang, and the lightweight trio lithium, beryllium and boron. 

Aspects of the chemical composition of the atmospheres of Jupiter, Saturn, Uranus, and Neptune were measured by the Voyager and Galileo spacecraft in the 1980s and 1990s,... 

Hydrogen isotopic compositions, expressed as molar D/H ratios, of solar system bodies. The relatively low D/H values in the atmospheres of Jupiter and Saturn are similar to those in the early Sun, whereas D/H ratios for Uranus and Neptune are intermediate between the Jupiter-Saturn values and those of comets and chondrites. The Earth s oceans have D/H shown by the horizontal line. Mars values are from SNC meteorites. Modified from Righter et al. (2006) and Lunine (2004). 

Diagram on the left shows the composition of the solar nebula (abundances in wt. %). Diagram on the right expands metals (astronomical jargon) into ices (water, methane, and ammonia) and rock (all other remaining elements). Jupiter and Saturn formed mostly from nebular gases, Uranus and Neptune formed mostly from ices, and the terrestrial planets formed primarily from rock. 

Jupiter and Uranus are outer planets composed mainly of gases. Jupiter s atmosphere contains reddish-brown clouds of ammonia. Uranus has an atmosphere made up mainly of hydrogen and helium with clouds of water vapor. This combination looks greenish to an outside observer. In addition, Mars has an atmosphere that is 95% carbon dioxide, and Venus has a permanent cloud cover of sulfur dioxide that appears pale yellow to an observer. Mercury has no permanent atmosphere. Saturn has 1 km thick dust and ice rings that orbit the planet. The eight planets in our solar system are diverse, each having different chemical compositions within and surrounding the planets. Out Earth is by far the friendliest planet for human existence. 

This Mercury is an ardent water, which has the power of dissolving all the composites, minerals and stones. And all that which resists other solvents, or strong waters, can be dissolved by the Scythe of Old Saturn which has caused the name of Universal Solvent to be given to it. 

He is the first perhaps who has taken such particular notice, what an augmentation of weight is added to many Preparations by the concurrence and incorporation of the substance of Fire into their composition, as you may see in the Calcination of Lead, p. 107. in the Distillation of Spirit of Saturn from the Salt of Saturn, p 116. in the Calcination of Regulus of Antimony, p 208. and even in the Calcination of Antimony by the heat of Sun with a burning glass, p 228. which few instances may possibly lead the way to Inquisitive persons to discover the same augmentation in divers other Preparations. ... 

Carbon based chemistry (organic chemistry) has thus been established to be of fundamental importance in interstellar molecular clouds. Similarly the observed composition of comets is dominated by carbon bearing molecules, and in the reducing atmospheres of Jupiter and Saturn the carbon chain molecules C2H2, CjH have been detected. 

The temperature profiles within Jupiter and Saturn are thought to be essentially adiabatic, reflecting the high central temperatures and the dominant role of convection below the observable atmosphere where radiative processes become important. There may be deeper layers restricted in radial extent where the temperature profile becomes subadiabatic, due to a decrease in the total opacity, or by virtue of the behavior of the equation of state of hydrogen and helium. The same may hold for Uranus and Neptune, although with less certainty, because of the possibility that stable compositional gradients could exist and dominate the heat flow regime. In particular, Uranus small heat flow, if primordial and not a function of seasonal insolation, could be the result of a stable compositional stratification and hence subadiabatic temperature profile in the interior (Podolak et al., 1991). 

Atreya S. K., Wong M. H., Owen T. C., Mahaffy P. R., Niemann H. B., de Pater I., Drossart P., and Encrenaz Th. (1999b) A comparison of the atmospheres of Jupiter and Saturn deep atmospheric composition, cloud structure, vertical mixing, and origin. Planet. Space Sci. 47, 1243-1262. 

Saturn s retinue of satellites is qualitatively quite different from Jupiter s fellow travelers. The system contains just one large satellite, Titan, which is virtually identical in bulk properties to Ganymede and Callisto. Titan s density, determined from Voyager observations, suggests a ice/rock composition and a probable differentiated interior by analogy with the Jupiter satellites. Titan s atmosphere, the first discovered for a planetary satellite, was detected in 1944 through identification of methane gas absorptions in its spectrum (Kuiper, 1944). 

Voyager density determinations from optical navigation and radio tracking (Smith et al., 1986 Tyler et al., 1986) suggest bulk compositions with both rock and ice. The proportions of the rock (including carbon constituents) are relatively high compared with the Saturn small satellites, 45-65% (Brown et al., 1991b Johnson et al., 1987). 

Figure 18 D/H ratios of several comets compared to the oceans (SMOW), planets, the solar nehula (PSN), and the interstellar medium. Low-temperature fractionation processes increase D/H. Jupiter and Saturn have compositions close to the original nehular composition, hut low-temperature formation of ice caused the enhancements seen in Uranus and Neptune (the ice giants) and comets. The discrepancy between the plotted LP comets and SMOW argues against these comets providing Earth with a major fraction of its water. Other comets, formed in warmer environments, near Jupiter, could he more similar to SMOW (source Huehner, 2002).

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