Surface of Titan revealed by Cassini/Huygens

Titan is Saturn's largest moon, and the second-largest natural satellite in the solar system. The surface is obscured from view by suspended haze layers, which are the products of methane photochemistry, within an atmosphere composed largely of molecular nitrogen and with a density exceeding that of Earth's. Titan thus affords a remarkable opportunity to understand the evolution of an organic-rich, planet-sized world with chemical cycles powered over geologic time by sunlight. Because of the difficulties of viewing the surface remotely, a full understanding of the nature of this complex world requires a campaign of in-situ and close flyby observations. The Cassini/Huygens payload is uniquely designed to conduct such an exploration from Saturn orbit and within Titan's atmosphere. Direct sampling of the atmospheric chemistry by gas-chromatography and mass spectroscopy will be complemented by global remote spectra collected in the UV through the infrared. Probe images in the optical and near-infrared right up to the point of impact will be complemented by Orbiter imagery in the near- infrared and through active radar sounding. The synergy between Orbiter and Probe observations required to do a first comprehensive exploration of Titan is a uniquely powerful capability of this mission.