Titan's surface spectra at the Huygens landing site and Shangri-La

P. Rannou, D. Toledo, P. Lavvas, E. D'Aversa, M. L. Moriconi, A. Adriani, S. Le Mouélic, C. Sotin, Robert H. Brown

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8 Scopus citations


Titan is an icy satellite of Saturn with a dense atmosphere and covered by a global photochemical organic haze. Ground based observations and the Huygens descent probe allowed to retrieve the main spectral signature of the water ice (. Griffith, C.A. et al. [2003]. Science 300(5619), 628-630; Coustenis, A. et al. [2005]. Icarus 177, 89-105) at the surface, possibly covered by a layer of sedimented organic material (Tomasko, M.G. et al. [2005]. Nature 438(7069), 765-778). However, the spectrum of the surface is not yet understood. In this study, we find that the surface reflectivity at the Huygens Landing Site (HLS) is well modeled by a layer of water ice grains overlaid by a moist layer of weakly compacted photochemical aggregated aerosols. Moist soils have spectra shifted toward short wavelengths relatively to spectra of dry soils. Cassini observations of Shangri-La region from orbit also show a very dark surface with a reflectivity peak shifted toward short wavelengths in respect to the reflectivity peak of bright surfaces, revealing a dichotomy between terrains based to their spectra in visible.

Original languageEnglish (US)
Pages (from-to)291-306
Number of pages16
StatePublished - May 15 2016



  • Photometry
  • surface
  • Titan

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Rannou, P., Toledo, D., Lavvas, P., D'Aversa, E., Moriconi, M. L., Adriani, A., Le Mouélic, S., Sotin, C., & Brown, R. H. (2016). Titan's surface spectra at the Huygens landing site and Shangri-La. Icarus, 270, 291-306. https://doi.org/10.1016/j.icarus.2015.09.016