Ah!! So I know the Jovian system are the *MOONS* of Jupiter. What I was missing is that a Jovian planet is a large gaseous planet, of which both Jupiter and Saturn would each be one. (Neptune and Uranus are the ice giants that qualify.) So, jovian system != Jovian planet. My bad. I had presumed most of the Nines activities to be restricted to Jovian systems (Jupiter's moon), rather than Jovian Planets. If it were the former, it is all the more strange they have this Outpost on a moon on another planet. If it is the latter meaning, not so strange. But still my original question was asking what is the significance of the Cauldron of Rhea. I presume we have no answer yet, then. But thanks for the replies!!