1. Release of volatiles from a possible cryovolcano from near-infrared imaging of Titan
- Author
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S. Lemouelic, P. D. Nicholson, Angioletta Coradini, Katrin Stephan, L. A. Soderblom, C.K. Scholz, Priscilla Cerroni, Yves Langevin, Giancarlo Bellucci, Robert H. Brown, Kevin H. Baines, Dale P. Cruikshank, Vittorio Formisano, Sebastien Rodriguez, Robert M. Nelson, Christophe Sotin, Pierre Drossart, Ralf Jaumann, Thomas B. McCord, Dennis L. Matson, Bruno Sicardy, Fabrizio Capaccioni, Bonnie J. Buratti, Jean-Pierre Bibring, M. Combes, Roger N. Clark, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Astrogeology Science Center [Flagstaff], United States Geological Survey [Reston] (USGS), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), NASA Ames Research Center (ARC), Department of Earth and Space Sciences [Seattle], and University of Washington [Seattle]
- Subjects
Solar System ,Extraterrestrial Environment ,010504 meteorology & atmospheric sciences ,[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,Infrared Rays ,Infrared ,cryovolcanism ,Saturnian satellites ,near-infrared ,01 natural sciences ,Methane ,Astrobiology ,symbols.namesake ,chemistry.chemical_compound ,0103 physical sciences ,Photography ,VIMS ,Spacecraft ,Atmosphere of Titan ,Moon ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,geography ,Multidisciplinary ,Life on Titan ,geography.geographical_feature_category ,Geography ,Atmosphere ,Ice ,Cryovolcano ,Hydrocarbons ,Satellites de Glace ,Saturn ,Volcano ,chemistry ,13. Climate action ,symbols ,Environmental science ,Cassini ,Gases ,Titan ,Titan (rocket family) - Abstract
The surface of Saturn's largest moon, Titan, is coated in a dense methane-rich atmosphere that prevents high-resolution imaging at visible wavelengths. During its first Titan flyby last October, the Cassini spacecraft's visual and infrared mapping spectrometer (VIMS) was able to reveal detailed surface structures, as reported in this issue. Notable features include a circular structure 30 km in diameter, thought to be a cryogenic dome. This may be volcanic, which could explain how the methane in Titan's atmosphere is replenished. Titan is the only satellite in our Solar System with a dense atmosphere. The surface pressure is 1.5 bar (ref. 1) and, similar to the Earth, N2 is the main component of the atmosphere. Methane is the second most important component2, but it is photodissociated on a timescale of 107 years (ref. 3). This short timescale has led to the suggestion that Titan may possess a surface or subsurface reservoir of hydrocarbons4,5 to replenish the atmosphere. Here we report near-infrared images of Titan obtained on 26 October 2004 by the Cassini spacecraft. The images show that a widespread methane ocean does not exist; subtle albedo variations instead suggest topographical variations, as would be expected for a more solid (perhaps icy) surface. We also find a circular structure ∼30 km in diameter that does not resemble any features seen on other icy satellites. We propose that the structure is a dome formed by upwelling icy plumes that release methane into Titan's atmosphere.
- Published
- 2005
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