Mapping and interpretation of Sinlap crater on Titan using Cassini VIMS and RADAR data

Research areas:
Year:
2008
Authors:
  • Stéphane Le Mouélic
  • Philippe Paillou
  • Michael A. Janssen
  • Jason W. Barnes
  • Sebastien Rodriguez
  • Christophe Sotin
  • Robert H. Brown
  • Kevin H. Baines
  • Bonnie J. Buratti
  • Roger N. Clark
  • Marc Crapeau
  • Pierre J. Encrenaz
  • Ralf Jaumann
  • Dirk Geudtner
  • Flora Paganelli
  • Laurence Soderblom
  • Gabriel Tobie
  • Steve Wall
Journal:
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
Volume:
113
Number:
E4
Month:
APR 12
ISSN:
0148-0227
Abstract:
Only a few impact craters have been unambiguously detected on Titan by
the Cassini-Huygens mission. Among these, Sinlap is the only one that
has been observed both by the RADAR and VIMS instruments. This paper
describes observations at centimeter and infrared wavelengths which
provide complementary information about the composition, topography, and
surface roughness. Several units appear in VIMS false color composites
of band ratios in the Sinlap area, suggesting compositional
heterogeneities. A bright pixel possibly related to a central peak does
not show significant spectral variations, indicating either that the
impact site was vertically homogeneous, or that this area has been
recovered by homogeneous deposits. Both VIMS ratio images and dielectric
constant measurements suggest the presence of an area enriched in water
ice around the main ejecta blanket. Since the Ku-band SAR may see
subsurface structures at the meter scale, the difference between
infrared and SAR observations can be explained by the presence of a thin
layer transparent to the radar. An analogy with terrestrial craters in
Libya supports this interpretation. Finally, a tentative model describes
the geological history of this area prior, during, and after the impact.
It involves mainly the creation of ballistic ejecta and an expanding
plume of vapor triggered by the impact, followed by the redeposition of
icy spherules recondensed from this vapor plume blown downwind.
Subsequent evolution is then driven by erosional processes and aeolian
deposition.