When
3:30 p.m., Nov. 30, 2010
Where
Kuiper Space Sciences 308
Ralf Kaiser, Professor at the University of Hawai'i at Manoa, is the scheduled speaker. Host: Roger Yelle.
The arrival of the Cassini-Huygens probe at Saturn’s moon Titan – the only Solar System body besides Earth and Venus with a solid surface and thick atmosphere – in 2004 opened up a new chapter in the history of Solar System exploration. Titan’s most prominent optically visible features are the aerosol-based haze layers, which give Titan its orange-brownish color. However, the underlying chemical processes, which initiate the haze formation, have been the least understood to date. This talk reviews recent laboratory studies on the role of polyacetylenes (polyynes) and (hetero) aromatic molecules like the phenyl radical, benzene, and pyridine in the formation of Titan’s organic haze layers utilizing crossed molecular beam experiments. Those investigations provide key concepts on the formation mechanisms of unsaturated hydrocarbon molecules – in particular ployynes and aromatic compounds – together with their hydrogen deficient precursors from the ‘bottom up’ in the atmosphere of Saturn’s moon Titan. A brief outline to future research directions tackling also the heterogeneous chemistry on Titan and in hydrocarbon-rich atmospheres in the outer Solar System in general will also be presented.
The arrival of the Cassini-Huygens probe at Saturn’s moon Titan – the only Solar System body besides Earth and Venus with a solid surface and thick atmosphere – in 2004 opened up a new chapter in the history of Solar System exploration. Titan’s most prominent optically visible features are the aerosol-based haze layers, which give Titan its orange-brownish color. However, the underlying chemical processes, which initiate the haze formation, have been the least understood to date. This talk reviews recent laboratory studies on the role of polyacetylenes (polyynes) and (hetero) aromatic molecules like the phenyl radical, benzene, and pyridine in the formation of Titan’s organic haze layers utilizing crossed molecular beam experiments. Those investigations provide key concepts on the formation mechanisms of unsaturated hydrocarbon molecules – in particular ployynes and aromatic compounds – together with their hydrogen deficient precursors from the ‘bottom up’ in the atmosphere of Saturn’s moon Titan. A brief outline to future research directions tackling also the heterogeneous chemistry on Titan and in hydrocarbon-rich atmospheres in the outer Solar System in general will also be presented.