Douglas P. Hamilton
Department of Astronomy, University of Maryland
The Origin of Titan and Hyperion
Titan is arguably the Solar System's most unusual satellite. It is fifty times more massive than Saturn's other moons and is the only satellite with a substantial atmosphere. Titan shares a unique resonance with nearby Hyperion, but otherwise sits in a particularly large gap between Rhea and Iapetus. Titan has the largest eccentricity of all Saturn's regular satellites and has a reasonably large orbital tilt; its distant neighbor Iapetus has an even more impressive eight degree free inclination. Hyperion itself is a mystery, with its unusual orbit, extremely low density and its unique surface covered with bizarre craters. None of these peculiarities are even partially understood. Until now!