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Organic chemistry on the surface of Titan


Some aspects of Titan’s organic chemistry are considered with particular emphasis on possible surface processing of organic species made in Titan’s upper atmosphere. Sources of energy include solar ultraviolet radiation, charged particles from the Saturnian magnetosphere, cosmic rays, winds and rain, hypervelocity impacts and (putatively) melting of crustal water ice (cryovolcanism). All of these sources, even those for which the energy is absorbed in the upper atmosphere, affect the surface, either directly or through the deposition of chemically reactive species sedimented out of the atmosphere in the form of aerosols. Once on the surface, organic molecules are immersed in a variety of different environments including dunes, mountains, river valleys, lakes and seas, which will affect the nature and outcome of chemical processes. All of the liquids in these environments are the light alkanes: methane, ethane, and propane. The organic chemistry ongoing in the surface system, should it be accessible for study, would provide an object lesson in the extent to which planetary environments drive or inhibit chemical complexity, with obvious application to the prebiotic Earth.

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We are grateful to Dr. Francois Raulin for his comments, which improved the manuscript. This work was financed within the scope of the program “Incentivazione alla mobilita’ di studiosi straineri e italiani residenti all’estero.”

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Correspondence to Jonathan I. Lunine.

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Lunine, J.I., Hörst, S.M. Organic chemistry on the surface of Titan. Rend. Fis. Acc. Lincei 22, 183–189 (2011).

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  • Organic molecules
  • Solar system
  • Titan
  • Saturn system
  • Cosmic rays
  • Organic chemistry