The Enceladus Plume Budget: Mass Flux, Kinetic Power and the Latent-Heat Cost of Sustaining the Jets

The plume that feeds Saturn's E ring carries a measurable mass flux, and every kilogram lifted carries energy costs that the south polar heat budget must pay. For vapour production of 200 kilograms per second the latent-heat cost alone is 566 megawatts and the kinetic power at 400 metres per second is 16 megawatts, together about 3.582 percent of the measured 15.8-gigawatt polar output for the latent term. At that loss rate the ocean reservoir lasts 2.94e+09 years even without resupply, so mass supply is not the constraint; energy and fracture plumbing are. The plume is energetically cheap relative to the heat that drives it. Computed from stated assumptions, not measured.