Io is one of the many moons orbiting Jupiter. The plume from Io’s volcanic eruptions can reach almost 500km high. Loki Patera is Io’s most powerful volcano, responsible for 10% of Io’s heat output. Scientists theorize that Io’s volcanic activity could be due to underground pockets of magma.
(https://on.natgeo.com/3gyVqX1, https://go.nasa.gov/3iq0BL8)