Tidal heating of Io

Io is the innermost of this set of resonant moons, and their interactions maintain its orbit in an eccentric (elliptical) state.

The friction-induced heating drives strong volcanic activities on the surface of Io.

[2] A study published in 2015, explains the eastern shift by an ocean of molten rock under the surface.

The team who wrote the paper believe that the subsurface ocean is a mixture of molten and solid rock.

This ability to generate heat in a subsurface ocean increases the chance of life on bodies like Europa and Enceladus.

Tidal heating on Io. (A) Of the four major moons of Jupiter, Io is the inner-most one. Gravity from these bodies pull Io in varying directions. (B) Io's eccentric orbit. Io's shape changes as it completes its orbit. (C) Earth's moon's orbit is actually more eccentric than Io's, but Earth's gravity is much weaker than Jupiter's, so Earth's moon does not experience as much deformation. [ 1 ]