The low temperature chemistry of Titan's atmosphere

Abstract

In Titan's atmosphere there is a permanent transformation of its major constituents, nitrogen (N2) and methane (CH4), into more complex organic compounds. We have conducted a series of experiments in which a simulated Titan's atmosphere enriched with trace gases (C2H2, C6H6, CO) was subjected to short-period cold-plasma irradiations at liquid nitrogen temperature in a continuous flow regime. The electric plasma is produced by a high voltage generator at positive and negative polarity and at a constant power of 8.83 Watts. The identification of organic compounds formed in gas phase was performed coupling the gas chromatography and mass spectrometry techniques. They include all the hydrocarbons and nitriles already detected in the satellite's atmosphere, particularly the unsaturated and aromatic ones, and some oxygenated compounds. The energetic yield for each one of the identified compound was calculated and contrasted with results of experiments performed during the last decade in different laboratories (Cabane and Chassefière, 1995; Coll et al., 1999; Ramírez et al., 2001; Ramírez et al., 2002) finding interesting remarks.