Does it feel like a reasonable "hook" to get players interested?
CERES, the largest asteroid, has always been the subject of intense scientific speculation. It ought to be a solid ball of ice, with a thin crust of meteoric dust, but there is evidence that there is liquid water under the crust; occasional plumes of ice crystals as jets of water boil off into space, and seismic noise that suggests slow internal activity.
Theory suggests that the ice layer is actually a mixture of ice and supercooled water, with some form of ‘antifreeze’ plus radioactive heat from the solid core keeping a portion of the ice from freezing. The structure predicted is a network of interconnected ice tunnels eroded by convection currents.
The last expedition detected a tunnel that matches this theoretical model, a few meters below the floor of a deep crevasse that penetrates the outer crust. Drilling revealed that it is roughly 50 meters wide, of indeterminate length, and has slow but detectable water currents.
This discovery makes it likely that it will be possible to explore the interior of the asteroid by submarine. Now that it is certain that there’s liquid water the Smithsonian Institute plans an expedition to the interior, and the SILGRS (Smithsonian Institution Low-Gravity Research Submarine) has moved from the drawing board to a finished vessel in less than a year.
Exploration of the interior is expected to produce a wealth of new information on the formation of the asteroids; if life is present, as seems possible, there may also be advances in biology, new and exciting pharmaceutical chemicals, and other sources of knowledge and profit. First, of course, someone needs to go inside and take a look.