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Titan's obliquity as evidence of a subsurface ocean?

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Baland, Rose-Marie [UCL] Van Hoolst, T. Yseboodt, M. Karatekin, Ö.

On the basis of gravity and radar observations with the Cassini spacecraft, the moment of inertia of Titan and the orientation of Titan's rotation axis have been estimated in recent studies. According to the observed orientation, Titan is close to the Cassini state. However, the observed obliquity is inconsistent with the estimate of the moment of inertia for an entirely solid Titan occupying the Cassini state. We propose a new Cassini state model for Titan in which we assume the presence of a liquid water ocean beneath an ice shell and consider the gravitational and pressure torques arising between the different layers of the satellite. With the new model, we find a closer agreement between the moment of inertia and the rotation state than for the solid case, strengthening the possibility that Titan has a subsurface ocean. © 2011 ESO.

Document type Article de périodique (Journal article) – Article de recherche
Access type Accès restreint
Publication date 2011
Language Anglais
Journal information "Astronomy & Astrophysics" - Vol. 530, p. A141 (2011)
Peer reviewed yes
Publisher E D P Sciences
issn 0004-6361
e-issn 1432-0746
Publication status Publié
Affiliation UCL - SST/ELI/ELIC - Earth & Climate
Links
  1. Baland Rose-Marie, Van Hoolst Tim, Librations of the Galilean satellites: The influence of global internal liquid layers, 10.1016/j.icarus.2010.04.004
  2. BILLS B, Free and forced obliquities of the Galilean satellites of Jupiter, 10.1016/j.icarus.2004.10.028
  3. Bills, B., & Nimmo, F. 2009, in European Planetary Science Congress 2009, 553
  4. Iess L., Rappaport N. J., Jacobson R. A., Racioppa P., Stevenson D. J., Tortora P., Armstrong J. W., Asmar S. W., Gravity Field, Shape, and Moment of Inertia of Titan, 10.1126/science.1182583
  5. Seidelmann, Series A, 26, 181 (2007)
  6. Stiles Bryan W., Kirk Randolph L., Lorenz Ralph D., Hensley Scott, Lee Ella, Ostro Steven J., Allison Michael D., Callahan Philip S., Gim Yonggyu, Iess Luciano, del Marmo Paolo Perci, Hamilton Gary, Johnson William T. K., West Richard D., Cassini RADAR Team The, DETERMINING TITAN'S SPIN STATE FROM CASSINI RADAR IMAGES, 10.1088/0004-6256/135/5/1669
  7. Stiles Bryan W., Kirk Randolph L., Lorenz Ralph D., Hensley Scott, Lee Ella, Ostro Steven J., Allison Michael D., Callahan Philip S., Gim Yonggyu, Iess Luciano, Perci del Marmo Paolo, Hamilton Gary, Johnson William T. K., West Richard D., Cassini RADAR Team The, ERRATUM: “DETERMINING TITAN'S SPIN STATE FROM CASSINI RADAR IMAGES” (2008, AJ, 135, 1669), 10.1088/0004-6256/139/1/311
  8. Szeto A. M. K., Xu S., Gravitational coupling in a triaxial ellipsoidal Earth, 10.1029/97jb02787
  9. Van Hoolst T., Rambaux N., Karatekin Ö., Baland R.-M., The effect of gravitational and pressure torques on Titan's length-of-day variations, 10.1016/j.icarus.2008.11.009
  10. Vienne, A&A, 297, 588 (1995)
Bibliographic reference Baland, Rose-Marie ; Van Hoolst, T. ; Yseboodt, M. ; Karatekin, Ö.. Titan's obliquity as evidence of a subsurface ocean?. In: Astronomy & Astrophysics, Vol. 530, p. A141 (2011)
Permanent URL http://hdl.handle.net/2078.1/163431