Io, Jupiter

Jupiter’s moon Io is the most volcanically active world in the Solar System. The gravitational tug-of-war between Jupiter and its other large moons squeezes Io so that its interior is molten.
The Juno mission has discovered remarkably strong activity on Jupiter's moon, Io. The hot spot emits eruptions with energy ...
NASA’s Juno mission to Jupiter’s moon Io has provided incredible data. A recent flyby revealed the most powerful volcanic event ever recorded on Io, the most volcanic world in our solar system.