Arctic Europa

Modeling of tidal processes on Europa, making use of observations recorded with the Galileo spacecraft, suggest that water could surge near the surface. This water would originate in the ocean thought to reside beneath the icy surface layer on Europa and well up in cracks caused by Europa's ongoing tidal battle with Jupiter. Thus the cracks might afford an avenue for an exchange of material and liquid between ocean and surface.

According to Richard Greenberg (University of Arizona, greenberg@lpl.arizona.edu), if living organisms existed at Europa they might be able to survive as close as a few tens of centimeters from the surface especially if they live in a crack where they could be bathed daily by water delivered by tides. Exploring for such biological samples would not then require deep drilling.

The nearness of water on Europa would therefore be more like that in Earth's Arctic basin, with ocean lying beneath riven and relatively thin ice sheets, rather than the Antarctic, where lake water is surmounted by kilometers-thick glacier. (Greenberg et al., Reviews of Geophysics, 6 September 2002.)