io, Juno and NASA

NASA’s Juno mission found Io’s biggest volcanic eruption ever. The explosion was stronger than all Earth’s power plants ...
Immense energy from frictional heating on Io melts portions of its interior, resulting in a seemingly endless series of lava ...
The gravitational tug-of-war between Jupiter and its other large moons squeezes Io so that its interior is molten. That magma finds its way to the surface in lava lakes and volcanic eruptions.