Linteolo inuoluta apud (potentia) Habitable Oceanum - Saturn’s moon Enceladus (et al)
Imagine an entire planet where every single spot on its surface is covered with water. Welcome to Enceladus. Enceladus is Saturn's sixth-largest moon and has an ocean sloshing between a rocky core and an icy crust. This is not pure conjecture; this is not a guesstimate (at least I don’t think so!) This is NASA having researchers of many disciplines share data, pour over that data and come to the shared conclusion that the ocean covers the entire planet.
Okay, so no it wasn’t like Europa with its water splashing out into space. This required Scientists to analyze seven years’ worth of high resolution images to track how the moon wobbles. (There was more data involved but this was the key data) Based on the seven years of data, they have concluded that the moon's ice crust must float freely from the core. And what would make that possible? It would only be possible if an ocean covered the entire world.
From the moons in our Galaxy, or at least in our solar system, many have hidden oceans. Most of the world’s that are on the fringe of our solar system-frozen worlds such as Pluto and many of Saturn’s moons, a hiding oceans below their frozen tundra. Consider that a planet’s angular momentum will push material towards its equator. So in a non-frozen world there would be a bulge along the equator. BUT because the ice would flow (in frozen worlds) reducing such an obvious protrusion, if a frozen world has such a bulge it actually signifies the absence of an ocean.
NASA is planning a future visit to Europa and while I am extremely excited for a mission that occurs in 2021-ish and arrives at Europa probably about 2027, I have the same kind of excitement regarding frozen worlds and alien life. (I don’t necessarily agree with all their reasons and one of my bigger reasons is the insulation from intense radiation.) Apparently the frozen ocean worlds under consideration also have the sorts of geological activity deemed necessary for life.
Now, in case you are wondering what geological activity or why here goes. The ingredients of life come out of a process. First theoretically, hot water interacts with rock. Rock leeches silica. Temperature drops and nanoparticles begin to form. To proceed, assuming the sunlight isn’t present, which may be lacking in a frozen world, to get energy and warmth one needs hydrothermal systems which are sets of processes that redistribute energy and mass in response to circulating H20 fluids. Systems such ones found in the oceanic and continental crusts and their fossilized equivalents. Heating Vents in a frozen ocean world constitute a substantial portion of the geologic record. It provides the building blocks, the recipe if you would, but if it ends up on with the desired results remains to be seen.
So grab your parka, your hand-warmers, an extra sweater is good, cause we’re going deep sea diving close to a light year from here! You game?