Europa subsurface ocean

Among places where condensates accreted into significant solid bodies, such as planets, habitable realms have always been rarer than places that were either too cold or too hot for life to exist. Much of our Solar System s mass is still far too hot for life. Most of the deep interiors of the gas giants and rocky planets are too hot, as is, of course, the Sun itself. Most of the surface area of solid bodies in the Solar System are too cold - the icy satellites of the outer planets and the myriad comets and Kuiper Belt Objects on the far outer fringes of the Solar System. In this sense, places like the surfaces of Earth and Mars and Europa s subsurface ocean are indeed very rare places. 

EP, Wagner R, Williams KK (1999) Does Europa have a subsurface ocean Evaluation of the geological evidence. J Geophy Res 104 24,015-24,055... 

In the Jovian system, the namre of the putative subsurface oceans of the icy satellites, particularly Europa, needs intensive future study. Issues include the thickness of liquid layers and ice crusts, the history of communication between liquid layers and the surface, and the brine composition of the liquid. The next mission planned to address these issues is the Jupiter Icy Moons Orbiter, which is designed to orbit each of the icy satellites and explore their surfaces and subsurfaces in detail. 

Khurana K. K., Kivelson M. G., Stevenson D. J., Schubert G., RussellC. T., Walker R. J., and Polanskey C. (1998) Induced magnetic fields as evidence for subsurface oceans in Europa and Callisto. Nature 395, 777-780. 

Zimmer C., Khurana K. K., and Kivelson M. G. (2000) Subsurface oceans on Europa and Callisto constraints from Galileo magnetometer observations. Icarus 147, 329-347. 

Melosh, H.J., Ekholm, A.G., Showman, A.R, Lorenz, R.D. Is Europa s subsurface water ocean warm In Lunar and Planetary Institute Conference Abstracts, vol. 33, p. 1824 (2002)... 

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