EGU21-13516, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

A chemical composition map for Titan’s surface

Anezina Solomonidou1,2,3, Athena Coustenis3, Rosaly Lopes4, Michael Malaska4, Alice Le Gall5,6, Bernard Schmitt7, Ashley Schoenfeld8, Steve Wall1, Kenneth Lawrence4, Christophe Sotin9, Christos Matsoukas10, Yannis Markonis2, Pierre Drossart3, and Charles Elachi1
Anezina Solomonidou et al.
  • 1California Institute of Technology (Caltech), Los Angeles, United States of America (
  • 2Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Suchdol, Praha, Czech Republic
  • 3LESIA–Observatoire de Paris, CNRS, UPMC Univ.Paris 06, Univ. Paris-Diderot, Meudon, France
  • 4Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
  • 5Institutde Physique du Globe de Paris (IPGP), CNRS-UMR 7154, Université Paris-Diderot, USPC, Paris, France
  • 6Institut Universitaire de France, Paris, France
  • 7Institut de Planétologie et d’Astrophysique de Grenoble, Université Grenoble Alpes, CNRS, Grenoble, France
  • 8Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, USA
  • 9Laboratoire Planétologie et Géodynamique, LPG Nantes, CNRS UMR 6112, Université de Nantes, Nantes, France
  • 10KTH-Royal Institute of Technology, Stockholm, Sweden

The investigation of Titan’s surface chemical composition is of great importance for the understanding of the atmosphere-surface-interior system of the moon. The Cassini cameras and especially the Visual and infrared Mapping Spectrometer has provided a sequence of spectra showing the diversity of Titan’s surface spectrum from flybys performed during the 13 years of Cassini’s operation. In the 0.8-5.2 μm range, this spectro-imaging data showed that the surface consists of a multivariable geological terrain hosting complex geological processes. The data from the seven narrow methane spectral “windows” centered at 0.93, 1.08, 1.27, 1.59, 2.03, 2.8 and 5 μm provide some information on the lower atmospheric context and the surface parameters. Nevertheless, atmospheric scattering and absorption need to be clearly evaluated before we can extract the surface properties. In various studies (Solomonidou et al., 2014; 2016; 2018; 2019; 2020a, 2020b; Lopes et al., 2016; Malaska et al., 2016; 2020), we used radiative transfer modeling in order to evaluate the atmospheric scattering and absorption and securely extract the surface albedo of multiple Titan areas including the major geomorphological units. We also investigated the morphological and microwave characteristics of these features using Cassini RADAR data in their SAR and radiometry mode. Here, we present a global map for Titan’s surface showing the chemical composition constraints for the various units. The results show that Titan’s surface composition, at the depths detected by VIMS, has significant latitudinal dependence, with its equator being dominated by organic materials from the atmosphere and a very dark unknown material, while higher latitudes contain more water ice. The albedo differences and similarities among the various geomorphological units give insights on the geological processes affecting Titan’s surface and, by implication, its interior. We discuss our results in terms of origin and evolution theories.

[1] Solomonidou, A., et al. (2014), J. Geophys. Res. Planets, 119, 1729; [2] Solomonidou, A., et al. (2016), Icarus, 270, 85; [3] Solomonidou, A., et al. (2018), J. Geophys. Res. Planets, 123, 489; [4] Solomonidou, A., et al. (2020a), Icarus, 344, 113338; [5] Solomonidou, A., et al. (2020b), A&A 641, A16; [6] Lopes, R., et al. (2016) Icarus, 270, 162; [7] Malaska, M., et al. (2016), Icarus 270, 130; [8] Malaska, M., et al. (2020), Icarus, 344, 113764.

How to cite: Solomonidou, A., Coustenis, A., Lopes, R., Malaska, M., Le Gall, A., Schmitt, B., Schoenfeld, A., Wall, S., Lawrence, K., Sotin, C., Matsoukas, C., Markonis, Y., Drossart, P., and Elachi, C.: A chemical composition map for Titan’s surface, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13516,, 2021.

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