2014 Annual Science Report
NASA Jet Propulsion Laboratory - Titan Reporting | SEP 2013 – DEC 2014
This is an interdisciplinary investigation of prebiotic chemistry on Titan in the context of Titan’s physical environment to provide a basis for understanding the prebiotic chemistry of the early Earth. Although Titan is far from the Sun and hence cold, solar radiation interacts with the methane rich atmosphere to initiate the formation of complex organic molecules and aerosols that eventually deposit on Titan’s geologically active surface, where further chemical evolution leading to the origin of life could occur.
The work comprised three parts or themes. The first theme, the current Titan physical environment, was aimed at understanding the basic physical processes that couple the surface and atmospheric chemistry of Titan. In the second theme, the complexity of atmospheric organic chemistry, employed experimental and theoretical tools to explore the range of atmospheric organic molecules that can be generated both in the gas-phase and in the condensed phase and subsequently deposited on the surface. The final theme of the proposed research, the evolving chemical state of the Titan surface, extended the state of knowledge of the prebiotic chemistry that might be ongoing at Titan’s surface. The themes were sequentially funded in time because the first theme led into the other two.
During the last year both Theme 2 and Theme 3 were completed. We developed a comprehensive model of the chemistry in Titan’s atmosphere including condensation of molecules onto grains and sublimation back to the gas, and exchange between the atmosphere and surface. Several papers are in progress and either have been or will shortly be submitted.
Theme 3 researchers continued to be extremely productive and many papers were published. Work focused on studies that elucidated chemical transformations that could occur on Titan’s surface, both spontaneously and through photochemical or electron-induced stimulation. Research on possible genetic polymers compatible with Titan surface conditions was completed. The team also made advances in situ techniques for detection of organics on Titan, using a novel atmospheric pressure ionization mass spectrometry technique.