Overview
- The Nature Astronomy study identifies Enceladus, Mimas and Miranda as small enough for under-ice boiling to occur.
- Cyclical tidal heating can melt and refreeze interiors, shrinking the moons as ice turns to water and lowering pressure at the ice–ocean boundary.
- Thresholds are modest, with boiling possible if Enceladus melts roughly 14 kilometers of ocean and Mimas about 5 kilometers.
- The effect is size dependent, as larger moons would keep water liquid or experience crustal failure before reaching boiling conditions.
- The fate of any vapor is unresolved, though gas bubbles may form and potentially influence surface features, with Mimas’ measured wobble offering a clue to a present ocean.