Rendiconti Lincei

, Volume 22, Issue 3, pp 183–189 | Cite as

Organic chemistry on the surface of Titan

Astrochemistry

Abstract

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.

Keywords

Organic molecules Solar system Titan Saturn system Cosmic rays Organic chemistry 

References

  1. Aharonson O, Hayes AG, Lunine JI, Lorenz RD, Allison MD, Elachi C (2009) An asymmetric distribution of lakes on Titan as a possible consequence of orbital forcing. Nature Geoscience 2:851–854CrossRefGoogle Scholar
  2. Bernard J-M (2004) Simulation expérimentale de la chimie atmosphérique de Titan. Thesis, Universite Paris 7 Google Scholar
  3. Brown RH, Lebreton J-P, Waite JH (eds) (2009) Titan from Cassini-Huygens. Springer, DordrechtGoogle Scholar
  4. Clark RN, Curchin JM, Barnes JW, Jaumann R, Soderblom L, Cruikshank DP, Brown RH, Rodriguez S, Lunine J, Stephan K, Hoefen TM, Le Mouelic S, Sotin C, Baines KH, Buratti BJ, Nicholson PD (2010) Detection and mapping of hydrocarbon deposits on Titan. J Geophys Res 115:E10005CrossRefGoogle Scholar
  5. Cordier D, Mousis O, Lunine JI, Lavvas P, Vuitton V (2009) An estimate of the chemical composition of Titan’s lakes. Astrophys J 707:L128–L131CrossRefGoogle Scholar
  6. FAO (2005) Energy conversion by photosynthetic organisms. Food and Agricultural Organization of the United Nations. http://www.fao.org/docrep/w7241e/w7241e06.htm#TopOfPage
  7. Hörst SM, Yelle RV, Buch A, Carrasco N, Cernogora N, Dutuit O, Quirico E, Sciamma-O’Brien E, Smith MA, Somogyi A, Szopa C, Thissen R, Vuitton V (2010) Formation of amino acids and nucleotide bases in a Titan atmosphere simulation experiment. Bull Am Astron Soc 42: p. 1068, abstr. 36.20Google Scholar
  8. Hueso R, Sanchez-Lavega A (2006) Methane storms on Saturn’s moon Titan. Nature 442:428–431CrossRefGoogle Scholar
  9. Lavvas P, Coustenis A, Vardavas I-P (2008) Coupling photochemistry with haze formation in Titan’s atmosphere, Part II: results and validation with Cassini/Huygens data. Planet Space Sci 56:67–99CrossRefGoogle Scholar
  10. Lorenz RD, Mitchell KL, Kirk RL, Hayes AG, Aharonson A, Zebker H, Paillou P, Radebaugh J, Lunine JI, Janssen M, Wall SD, Lopes RM, Stiles B, Ostro S, Mitri G, Stofan ER (2008) Titan’s inventory of organic surface materials. Geophys Res Lett 35:L02206CrossRefGoogle Scholar
  11. Lorenz RD, Newman C, Lunine JI (2010) Threshold of wave generation on Titan’s lakes and seas: Effect of viscosity and implications for Cassini observations. Icarus 207:932–937CrossRefGoogle Scholar
  12. Lunine JI, Choukron M, Stevenson DJ, Tobie G (2009) The origin and evolution of Titan. In: Brown RH, Lebreton JP, Waite H (eds) Titan from Cassini-Huygens. Springer, Dordrecht, pp 35–59CrossRefGoogle Scholar
  13. Lunine J, Artemieva N, Tobie G (2010) Impact cratering on Titan: hydrocarbons versus water. LPSC 41: abstr. 1533Google Scholar
  14. Lunine J, Reh K, Sotin C, Couzin P, Vargas A (2011) Titan aerial explorer: a mission to circumnavigate Titan. LPSC 42: abstr. 1230Google Scholar
  15. Matteson DS (1983) Acetylene on Titan. Science 223:1131CrossRefGoogle Scholar
  16. McKay CP, Smith H (2005) Possibilities for methanogenic life in liquid methane on the surface of Titan. Icarus 178:274–276CrossRefGoogle Scholar
  17. Mitri G, Showman AP, Lunine JI, Lopes RMC (2008) Resurfacing of Titan by ammonia–water cryomagma. Icarus 196:216–224CrossRefGoogle Scholar
  18. Neish C, Somogyi A, Smith MA (2010) Titan’s primordial soup: Formation of amino acids via low-temperature hydrolysis of tholins. Astrobiology 10:337–347CrossRefGoogle Scholar
  19. Niemann HB, Atreya SK, Demick JE, Gautier D, Haberman JA, Harpold DN, Kasprzak WT, Lunine JI, Owen TC, Raulin F (2010) Composition of Titan’s lower atmosphere and simple surface volatiles as measured by the Cassini Huygens probe gas chromatograph mass spectrometer experiment. J Geophys Res 115:E12006CrossRefGoogle Scholar
  20. Nimmo F, Bills BG (2010) Shell thickness variations and the long-wavelength topography of Titan. Icarus 208:896–904CrossRefGoogle Scholar
  21. Ramirez SI, Coll P, Buch A, Brassé C, Poch O, Raulin F (2010) The fate of aerosols on the surface of Titan. Faraday Discuss 147:419–427CrossRefGoogle Scholar
  22. Raulin F, Hand KP, McKay CP, Viso M (2010) Exobiology and planetary protection of icy moons. Space Science Reviews 153:511–535CrossRefGoogle Scholar
  23. Stofan E, Lorenz RD, Lunine JI, Aharanson O, Bierhaus E, Clark B, Griffith C, Harri A-M, Karkoschka E, Kirk R, Kantsiper B, Mahaffy P, Newman C, Ravine M, Trainer M, Waite JH, Zarnecki J (2010) Titan Mare Explorer: First in situ exploration of an extraterrestrial sea. Astrobiology Science Conf., League City,TX. Abstr. 5270Google Scholar
  24. Tomasko MG, Archinal B, Becker T, Bézard B, Bushroe M, Combes M, Cook D, Coustenis A, de Bergh C, Dafoe LE, Doose L, Douté S, Eibl A, Engel S, Gliem F, Grieger B, Holso K, Howington-Kraus E, Karkoschka E, Keller HU, Kirk R, Kramm R, Küppers M, Lanagan P, Lellouch E, Lemmon M, Lunine JI, McFarlane E, Moores J, Prout GM, Rizk B, Rosiek M, Rueffer P, Schröder SE, Schmitt B, See C, Smith P, Soderblom L, Thomas N, West RA (2005) Rain, winds and haze during the Huygens probe’s descent to Titan’s surface. Nature 438:765–778CrossRefGoogle Scholar
  25. Turtle EP, Perry JE, Hayes AE, Lorenz RD, Barnes JW, McEwen AS, West RA, Del Genio AD, Barbara JM, Lunine JI, Schaller EL, Ray TL, Lopes RMC, Stofan ER (2011) Rapid and extensive surface changes near Titan’s equator: Evidence of April showers. Science in pressGoogle Scholar
  26. Wood CA, Lorenz R, Kirk R, Lopes R, Mitchell K, Stofan E, the Cassini Radar team et al (2010) Impact craters on Titan. Icarus 206:334–344CrossRefGoogle Scholar
  27. Yung YL, Allen MA, Pinto JP (1984) Photochemistry of the atmosphere of Titan: Comparison between models and observations. Ap J Suppl 55:465–506CrossRefGoogle Scholar
  28. Zhou L, Zheng W, Kaiser R, Landera A, Mebel AM, Liang M-C, Yung YL (2010) Cosmic-ray-mediated formation of benzene on the surface of Saturn’s moon Titan. Ap J 718:1243–1251CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Dipartimento di FisicaUniversità degli Studi di Roma “Tor Vergata”RomeItaly
  2. 2.Lunar and Planetary LaboratoryThe University of ArizonaTucsonUSA

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