The composition and origin of Titan's atmosphere

摘要: Abstract The discovery that Titan had an atmosphere was made by the identification of methane in satellite's spectrum 1944. But abundance this gas and other major constituents required 1980 encounter Voyager 1 spacecraft. In intervening years, traces C2H2, C2H4, C2H6 CH3D been posited to interpret emission bands Titan's i.r. spectrum. Infra-red Spectrometer confirmed these gases were present added seven more. is now known be composed primarily molecular nitrogen. derived mean weight suggests presence a significant amount some heavier gas, most probably argon. It shown argon must primordial, one can understand evolution terms degassing mixed hydrate dominated CH4, N2 36Ar. This model satisfactorily explains absence neon makes no special requirements on surface temperature.