4. The moons of giant planets

The giant planets Jupiter, Saturn, Uranus, and Neptune each have an extensive entourage of moons: small inner moonlets, closest to the planets, mostly less than a few tens of kilometres in radius and irregular in shape; next are large regular satellites exceeding about 200 km in radius; and then there are the irregular satellites mostly less than a few tens of kilometres in radius. ‘The moons of giant planets’ describes these different types of moons, the space missions to find them, their orbital resonance and tidal heating, as well as the spectacular and complex rings and shepherd moons of Saturn and the other giant planets.