International audienceTitan is the biggest satellite of Saturn whose atmosphere is mainly composed of molecularnitrogen (N2) and methane (CH4) with an average ratio of 98/2 %. The Cassini/Huygens mission revealed that the interaction between those neutral moleculesand the UV solar light leads to a complex photochemistry that produces heavy organicmolecules. When those molecules condense, they will then become the solid aerosols whichare responsible for the brownish haze surrounding Titan. Between 1000 and 600km, the VUV solar radiations are still significant and will continueto modify the physical, chemical and optical properties of those grains. A change in theseparameters can impact the radiative budget of Titan’s atmosphere