History and Geography

The Plumes

    • Predominantly water
    • Trace amounts of ammonia and light organics (e.g. propane)
    • Possible stratification in particle size with altitude above the surface

This would indicate that the largest near-surface droplets are frozen droplets of salty liquid water.

A Subsurface Ocean

An analysis of small silicon-containing E-ring particles indicates hydrothermal sources at the boundary between the ocean and the core.

Evidence indicates a sub-ice-shell liquid water ocean with salinity comparable to Earth’s ocean. This ocean would be in contact with the moon’s rocky core, serving as the source of the materials erupting from geysers.