This session welcomes papers about the outer planets and Pluto, and their satellites with atmospheres, with special emphasis on observations (both from space and from the ground), modelling, and theoretical interpretation. Among the outer planet satellites we consider in this session those in the Outer Solar System that are geologically active, show time variable properties, and have a tenuous or thick gaseous environment or plumes. Thus, Titan with its thick nitrogen atmosphere is found to have seasonal changes as monitored by the Cassini spacecraft since 2004. Enceladus radiates more heat than can be fully explained (as does Io) and expels a plume of water vapor and other constituents from its southern pole. Europa’s surface shows signs of relatively recent geological activity and carries a tenuous oxygen atmosphere. Similarly, Ganymede (and possibly Callisto), has a small oxygen atmosphere, but also its own magnetosphere, and the internal activity that is necessary to generate its magnetic field. Neptune's moon Triton has a nitrogen-methane atmosphere, much like Titan, but with a pressure that is more Pluto-like. Abstracts on satellite interactions with their neutral environments, supporting laboratory investigations and concepts for future spacecraft missions and investigations are also relevant to this session. Note the special event on the Cassini mission in PS3.2