Titan

Preliminary results on surface properties and photometry from VIMS observations of the early flybys

B. J. Buratti, C. Sotin, Robert H. Brown, M. D. Hicks, R. N. Clark, J. A. Mosher, T. B. McCord, R. Jaumann, K. H. Baines, P. D. Nicholson, T. Momary, D. P. Simonelli, B. Sicardy

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Cassini observations of the surface of Titan offer unprecedented views of its surface through atmospheric windows in the 1-5 μm region. Images obtained in windows for which the haze opacity is low can be used to derive quantitative photometric parameters such as albedo and albedo distribution, and physical properties such as roughness and particle characteristics. Images from the early Titan flybys, particularly T0, Ta, and T5 have been analyzed to create albedo maps in the 2.01 and 2.73 μm windows. We find the average normal reflectance at these two wavelengths to be 0.15±0.02 and 0.035±0.003, respectively. Titan's surface is bifurcated into two albedo regimes, particularly at 2.01 μm. Analysis of these two regimes to understand the physical character of the surface was accomplished with a macroscopic roughness model. We find that the two types of surface have substantially different roughness, with the low-albedo surface exhibiting mean slope angles of ∼18°, and the high-albedo terrain having a much more substantial roughness with a mean slope angle of ∼34°. A single-scattering phase function approximated by a one-term Henyey-Greenstein equation was also fit to each unit. Titan's surface is back-scattering (g∼0.3-0.4), and does not exhibit substantially different backscattering behavior between the two terrains. Our results suggest that two distinct geophysical domains exist on Titan: a bright region cut by deep drainage channels and a relatively smooth surface. The two terrains are covered by a film or a coating of particles perhaps precipitated from the satellite's haze layer and transported by eolian processes. Our results are preliminary: more accurate values for the surface albedo and physical parameters will be derived as more data is gathered by the Cassini spacecraft and as a more complete radiative transfer model is developed from both Cassini orbiter and Huygens Lander measurements.

Original languageEnglish (US)
Pages (from-to)1498-1509
Number of pages12
JournalPlanetary and Space Science
Volume54
Issue number15
DOIs
StatePublished - Dec 2006

Fingerprint

Titan
surface properties
photometry
albedo
roughness
haze
slope angle
scattering
slopes
atmospheric windows
eolian process
distribution (property)
drainage
opacity
radiative transfer
coating
reflectance
backscattering
spacecraft
physical property

Keywords

  • Cassini mission
  • Saturnian satellites
  • Titan

ASJC Scopus subject areas

  • Geophysics
  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Titan : Preliminary results on surface properties and photometry from VIMS observations of the early flybys. / Buratti, B. J.; Sotin, C.; Brown, Robert H.; Hicks, M. D.; Clark, R. N.; Mosher, J. A.; McCord, T. B.; Jaumann, R.; Baines, K. H.; Nicholson, P. D.; Momary, T.; Simonelli, D. P.; Sicardy, B.

In: Planetary and Space Science, Vol. 54, No. 15, 12.2006, p. 1498-1509.

Research output: Contribution to journalArticle

Buratti, BJ, Sotin, C, Brown, RH, Hicks, MD, Clark, RN, Mosher, JA, McCord, TB, Jaumann, R, Baines, KH, Nicholson, PD, Momary, T, Simonelli, DP & Sicardy, B 2006, 'Titan: Preliminary results on surface properties and photometry from VIMS observations of the early flybys', Planetary and Space Science, vol. 54, no. 15, pp. 1498-1509. https://doi.org/10.1016/j.pss.2006.06.015
Buratti, B. J. ; Sotin, C. ; Brown, Robert H. ; Hicks, M. D. ; Clark, R. N. ; Mosher, J. A. ; McCord, T. B. ; Jaumann, R. ; Baines, K. H. ; Nicholson, P. D. ; Momary, T. ; Simonelli, D. P. ; Sicardy, B. / Titan : Preliminary results on surface properties and photometry from VIMS observations of the early flybys. In: Planetary and Space Science. 2006 ; Vol. 54, No. 15. pp. 1498-1509.
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AU - Clark, R. N.

AU - Mosher, J. A.

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