Abstract

Saturn’s moon Titan is the only moon of the Solar System to possess a dense atmosphere, quite similar to Earth’s atmosphere in its composition (mainly nitrogen), its thermal structure, and its methane cycle analogous to Earth’s water cycle. Titan’s atmosphere hosts a complex photochemistry, which produces many hydrocarbons (e.g C2H6 , C4H2, C6H6 …) and nitriles (such as HCN , or HC3N ) which react further together to form organic hazes (particles in suspension in the atmosphere). Like Earth, Titan’s atmosphere undergoes seasonal variations of insolation over its orbit around the Sun (29.5 years), which are expected to affect its temperature and composition. During almost half a Titan year (2004-2017), the Cassini spacecraft monitored Titan’s atmosphere, hence providing us with an unprecedented opportunity to study its climate and its seasonal evolution from northern winter to summer solstice. In this seminar, I will present the new insights on Titan’s atmospheric chemistry and dynamics gained from the Cassini mission and how they shape current and future studies of Titan’s atmosphere.