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Title: Does Titan have a global liquid ocean or a slushy interior?
Plain: Cassini measured how much Titan, Saturn's largest moon, is squeezed by Saturn's tides, and the large response was first read as a sign of a hidden global ocean. A 2025 reanalysis argues instead for a slushy layer of ice with pockets of water.
Precise: Determine from Titan's tidal Love number $k2$, the tidal phase lag and the rotation state whether its interior contains a global liquid water ocean decoupled from the ice shell or a high-pressure-ice layer containing partial melt, and constrain the hydrosphere structure. An answer is an interior model that matches $k2$, dissipation and obliquity data and excludes the alternative.
Settled by: Independent measurements of Titan's tidal response and dissipation, for example from Dragonfly geophysics, together with consistent rheological models.
Kind: well-posed
Answer type: classification
References: (empty)
Literature status: contested
Status note: Petricca et al. 2025 (Nature) argued that strong tidal dissipation in Cassini data precludes a global subsurface ocean.
Posed since: (empty)