Cordilleran Section - 113th Annual Meeting - 2017

Paper No. 20-7
Presentation Time: 4:05 PM


SOLOMONIDOU, Anezina1, LOPES, Rosaly2, COUSTENIS, A.3, RADEBAUGH, Jani4, RODRIGUEZ, Sebastien3, BRATSOLIS, Emmanuel5, MALASKA, Michael J.6, SCHMITT, B.7, DROSSART, Pierre8, BROWN, Robert9 and MATSOUKAS, Christos10, (1)Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 183-601, 4800 Oak Grove Dr, Pasadena, CA 91109, (2)Jet Propulsion Laboratory, (3)Observatoire Paris-Meudon, France, (4)Department of Geological Sciences, Brigham Young University, Provo, UT 84602, (5)Physics, University of Athens, Athens, 92001, Greece, (6)Jet Propulsion Laboratory/California Institute of Technology, Mail Stop 183-301, 4800 Oak Grove Drive, Pasadena, CA 91109, (7)Université Grenoble Alpes, CNRS, Grenoble, France, (8)Observatoire Paris-Meudon, Observatoire Paris-Meudon, Observatoire Paris-Meudon, France, (9)Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, (10)KTH-Royal Institute of Technology, Stockholm, Sweden,

Cassini’s Visual and Infrared Mapping Spectrometer (VIMS) and the RADAR have been investigating Titan’s surface since 2004. Both instruments unveiled the dynamic and complex surface expressions of this Saturnian moon, suggesting exogenic and endogenic processes [1;2;3]. In order to evaluate the atmospheric contribution and thereafter extract surface information, a Radiative transfer code is used to analyse different regions and to monitor their spectral behaviour over time [4;5;8]. We furthermore use RADAR/SAR images to infer information on the morphology [6;7]. We find that temporal variations of surface albedo occur for some areas, but that their origin may differ from one region to the other. Tui Regio and Sotra Patera change with time becoming darker and brighter respectively in terms of surface albedo. In contrast, we find that the undifferentiated plains and the suggested evaporitic areas in the equatorial regions do not present any significant change [5]. The observation of surface brightening at Sotra supports a possible internal rather than an exogenic origin. Our results support the hypothesis that Titan has had cryovolcanism and may still be having some degassing or other activity, though other explanations for the brightening cannot be ruled out. Potential sources of the energy for cryovolcanism include tidal heating, possible internal convection, and ice tectonics, is believed to be a pre-requisite of a habitable planetary body as it allows the recycling of minerals and potential nutrients and provides localized energy sources. A study by Sohl et al. (2014) has shown that tidal forces are a constant and significant source of internal deformation on Titan and the interior liquid water ocean can be relatively warm for reasonable amounts of ammonia concentrations [9].

References: [1] Lopes, R.M.C., et al. JGR, 118, 416-435, 2013 [2] Solomonidou, A., et al. PSS, 70, 77-104, 2013 [3] Moore, J.M. and Howard, A.D. GRL, 37, L22205, 2010 [4] Solomonidou, A., et al. JGR, 119, 1729-1747, 2014 [5] Solomonidou, A., et al. Icarus, 270, 85-99, 2016 [6] Lopes, R.M.C., et al. Icarus, 270, 162-182, 2016 [7] Malaska, M., et al.: Icarus, 270, 130-161, 2016. [8] Hirtzig, M., et al. Icarus, 226, 470-486, 2013 [9] Sohl, F., et al. JGR, 119, 1013-1036, 2014.