Volcanoes provide an efficient way for solid planets and moons to shed their internal heat. Much of this heat arises from radioactivity in their interiors. Some moons are also heated by internal friction due to gravitational forces from their host planet. Volcanism has occurred on all the terrestrial planets and on the larger moons, causing extensive resurfacing on some of them. Jupiter’s moon Io is the most volcanically active world in the solar system.
Keywords: Radioactivity, Volcanism, Moon, Planets, Satellites, Io (Satellite), Extrasolar planets, Astrogeology