Tidal Love numbers of membrane worlds: Europa, Titan, and Co.

摘要: Abstract Under tidal forcing, icy satellites with subsurface oceans deform as if the surface were a membrane stretched around fluid layer. ‘Membrane worlds’ is thus fitting name for these bodies and theory provides perfect toolbox to predict effects. I describe here new approach perturbations based on general of viscoelastic–gravitational deformations spherically symmetric bodies. The massive leads explicit formulas viscoelastic Love numbers which are exact in limit zero crust thickness. Formulas load come bonus. accuracy k 2 h better than one percent thickness less five percents radius, probably case Europa Titan. allows density differences between ocean correctly includes compressibility. This last feature makes it more accurate incompressible propagator matrix method. Membrane factorize shallow deep interior contributions, latter affecting mainly through stratification. show that screening effect explains why stratification typically increases instead reducing them. For Titan, thin dense liquid layer at bottom light can raise by ten percents. also deal dynamical tides non-rotating body. resonance significantly decreases tilt factor may lead underestimating Europa’s Finally, heating order few hundred meters.