Another ocean-moon in our solar system? Or not?

Pictures from various probes have shown saltwater geysers on Saturn's moon Enceladus, shooting columns of water high into the sky. Some scientists have suggested that Enceladus- like three of Jupiter's four largest moons, Ganymede, Callisto and Europa- has an ocean beneath its frozen crust, which may harbor life.

But a dissent comes from scientists at the University of Colorado at Boulder, whose studies of the sodium content of the water from the geysers based on their photographic spectra make them suspect otherwise. It may simply be that the moon merely harbors underground caverns full of brine.

Either way, the moons of our system's gas giants are turning out to be fascinating worlds indeed.
Enceladus, incidentally, is one of two moons in our solar system- Saturn's largest moon, Titan, being the other- known to have a significant atmosphere.