Sagittarius role, after the introspection of Scorpio is to take the hard won wisdom and create something worthwhile from it and spread it around.
Europa: Planetary scientists generally think that a layer of liquid water swirls around beneath Europa's surface, and that heat from tidal flexing causes the subsurface ocean to remain liquid. It is estimated that the outer crust of solid ice is about 6 to 19 miles thick, including a ductile "warm ice" layer that hints that the liquid ocean underneath may be 60 miles deep. This means that Europa's oceans would amount to slightly more than two times the volume of Earth's oceans.
The astronomers found that larger craters, which excavated pits much deeper into the Moon's surface, only increased porosity in the underlying crust. This indicates that these deeper layers have not reached a steady state in porosity, and are not as fractured as the megaregolith.