Jupiter interior model

Stevenson, D. J. Salpeter, E. E. (1976). Interior models of Jupiter. In Jupiter, ed. T. Gehrels, pp. 85-112. Tucson The University of Arizona Press. 

Models of the interiors of the giant planets depend on assumed temperature-pressure-density relationships that are not very well constrained. Models for Jupiter and Saturn feature concentric layers (from the outside inward) of molecular hydrogen, metallic hydrogen, and ice, perhaps with small cores of rock (rocky cores are permissible but not required by current data). Uranus and Neptune models are similar, except that there is no metallic hydrogen, the interior layers of ice are thicker, and the rocky cores are relatively larger. 

Figure 1 Some known giant planets and brown dwarfs, illustrated with a limited azimuthal slice (pie slice) to correct scale. The interiors are color coded according to the principal materials in each zone. Ice and rock refer to elements common in materials that are icy or rocky at normal pressures. Metallic hydrogen indicates ionization primarily through pressure effects. Modeled central temperature in K, and pressure in 10 bar, is shown. The radii of all but G1229b are known directly for G1229b, modeling of the brightness versus wavelength must be used to derive the radius. From left to right, the masses (expressed relative to the mass of Jupiter) are 45,1, 0.7, 0.3, and 0.05...

For Saturn versus Jupiter the story is a bit clearer. Models of the interior and evolution of Jupiter (described further below) produce the currently observed effective temperature with only sunlight and the original virialized energy of collapse no additional differentiation is required at present. However, in the case of Saturn, additional energy is required to obtain a body of its effective temperature and mass at an age of 4.56 Gyr, implying that differentiation is... 

Figure 9 Comparison of silicate mass fractions. Two assumptions for interior strueture are shown (i) differentiated—rock core, ice mantle, and (ii) homogeneous—uniformly mixed ice and roek. Also shown are silicate mass fractions for the Jupiter and Saturn systems and expected values for two models of the early solar nebula carbon chemistry (see text) (after Johnson et aL, 1987) (reproduced by permission of Ameriean Geophysieal Union from /. Geophys. Res. Space Phys. 1987, 92, 14884-14894).

It is possible to model molecules or structures that only exist at high temperatures and/or high pressures or are too dangerous to handle. Theoretical methods have been used, for example, to predict that at the temperatures and pressures in the interior of the planet Jupiter (Figure 1.2), hydrogen can exist as a liquid metal. Conditions under which such a form of hydrogen would occur were not achieved experimentally on Earth until 1996. 

Vapour pressure osmometry VPO). At present commercially available apparatus for VPO is the Corona molecular-weight apparatus models 114 and 117 manufactured by the Corona Co., which have been produced in the past by Hitachi Co. Ltd Knauer Vapour Pressure Osmometer No. 731.110000 (Dr. H. Knauer Wissenschaftliche Cerate, AG) Jupiter Model 233 Vapour Pressure Osmometer (Jupiter Instrument Co. Inc.) and Gonotec model 070 (Gonotec Gesellschaft fiir MeB- und Regeltechnik m6H). A typical VPO apparatus consists of (1) two thermistors covered with glass, to which solution and solvent drops are attached (2) a cell, the interior of which is saturated with solvent vapour (3) a solvent vessel, placed at the lower part of the cell and (4) an electronic circuit. The instrument is usually thermostatted. 

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