| Abstract: | The phase behavior of multicomponent gas mixtures is far more complex than that of pure gases. It follows that the physical structure and hydrodynamic behavior of planets composed of mixtures of gases can be far more complex than has been suggested by models developed around the framework of a body of pure hydrogen. At high pressures, mixtures of gases often exhibit limited mutual solubility, not only between solid and fluid phases, but also between coexisting fluid phases as well. In binary mixtures in which the more volatile component has the higher molecular weight, a reversal in the relative densities of coexisting fluid and solid phases can occur at high pressures because of differences in the effects of pressure on solubilities in the two phases. The results of recent laboratory experiments on phase behavior in mixtures of gases at high pressures are reviewed, and attention is drawn to their implications for the deep atmosphere and interior structures of the other planets. |
