Atmospheres of Solar System Moons and Pluto

Abstract

The atmospheres within our Solar System can be categorized into four distinct climate regimes: "terrestrial", "Jovian", "condensable", and "exosphere". Beyond the three terrestrial planets (excluding Mercury) and the four giant planets, collisional atmospheres are also found on smaller celestial bodies such as Jupiter's moon Io, Saturn's moon Titan, Neptune's moon Triton, and Pluto. This article reviews the key characteristics of these atmospheres and the underlying physical and chemical processes that govern them. I focus on their thermal structures, chemical constituents, wind patterns, and the origins and losses of the atmospheres, and highlight the critical roles of surface ices and liquids, atmospheric hazes, and the space environments of their host planets in shaping these atmospheres. I dedicated this article to Prof. Zuo Xiao (1936-2024) at Peking University.