Rings, Moons, and Pluto (Astronomy)

Recall cards on the moon and ring systems of the giant planets, and on the dwarf planet Pluto. The four Galilean moons of Jupiter: heavily cratered Callisto, giant Ganymede, ocean-bearing Europa, and volcanic Io, whose eruptions are driven by tidal heating. Saturn's moons, including Titan with its thick nitrogen atmosphere and hydrocarbon lakes, and Enceladus with its water geysers and subsurface ocean. Neptune's captured moon Triton, the coldest world yet visited, with its nitrogen geysers. Pluto and its large moon Charon, in a double tidal lock, explored by New Horizons in 2015. And the planetary ring systems: the bright, broad water-ice rings of Saturn with the Cassini Division, the dark narrow rings of Uranus and Neptune, and how orbital resonances and shepherd moons sculpt them.