Io, Europa and Enceladus Stay Active Through 100-Metre Tidal Flexing
Updated
Updated · spacedaily.com · Aug 20
Io, Europa and Enceladus Stay Active Through 100-Metre Tidal Flexing
3 articles · Updated · spacedaily.com · Aug 20
Summary
Io, Europa and Enceladus remain internally active because giant-planet gravity repeatedly flexes their interiors, generating heat even far from the Sun.
100-metre tidal rises on Io show the scale of that stress: slightly eccentric orbits keep each moon being squeezed and relaxed, while orbital resonances prevent the motion from damping away.
Io channels the energy into hundreds of volcanoes, Europa likely uses part of it to help maintain a salty ocean beneath 15 to 25 kilometres of ice, and Enceladus vents water and ice from south-polar fractures.
30 gigawatts from tidal friction in Enceladus's porous rocky core could explain its warm south pole and plume activity, making it one of the few ocean worlds whose subsurface material can be sampled directly.
The broader implication is that internal activity depends not just on sunlight but on orbital architecture—though the heating is sustained by evolving orbital energy, not a perpetual process.