NASA Europa Missions, projects and proposals for the 2020s Options

[MahFL]

Yahoo News

[TheAnt]

@monitorlizard: A laser altimeter would be great on one spacecraft that orbit Europe. Yet this spacecraft will orbit Jupiter and only do flyby's of Europa.

@JRehling: Yes that Europa might have water closer to the surface would fit some observations of surface features such as the chaos terrain, at the same time having a thick ice over the ocean closer to the core.
Dual layers of ice have been noted in the arctic ocean as well as in sweet water lakes in the arctic and sub-arctic region. On lakes here on Earth the energy source generally comes from above, the sun that melts snow on the surface to freeze to create the second ice sheet. On Europa the energy would come from below.
On a few rare cases I seen double ice formed from a spring of water at the bottom of the lake in lime rich areas, the icesheet formed at the inversion layer in deeper water of the lake. At least to me that provided a model of how a double ice layer might form. Blankenship Schmidt and Schenk provided a very nice model for those melt lenses, but the intermediate layer of water might be more widespread.