Enceladus' hidden ocean may have stayed warm long enough for life
Enceladus, a ~500-km Saturnian moon, vents water vapour and ice grains from a global salty ocean beneath its ice shell. Cassini data reveal molecular hydrogen—a sign of hydrothermal activity—and 2023 analyses detected phosphates, supplying essential ingredients for life. Modelling suggests tidal heating could keep the ocean warm and chemically active for geological timescales, meaning there could have been a long window for life to emerge—though this is about opportunity, not evidence of life. Proposals for missions to sample the plume or surface exist, but for now the headline is that a tiny moon may hide a long-lived, life-friendly ocean.