Gravity Field, Shape, and Moment of Inertia of Titan
Abstract
Precise radio tracking of the spacecraft Cassini has provided a determination of Titan's mass and gravity harmonics to degree 3. The quadrupole field is consistent with a hydrostatically relaxed body shaped by tidal and rotational effects. The inferred moment of inertia factor is about 0.34, implying incomplete differentiation, either in the sense of imperfect separation of rock from ice or a core in which a large amount of water remains chemically bound in silicates. The equilibrium figure is a triaxial ellipsoid whose semi-axes a, b, and c differ by 410 meters (a – c) and 103 meters (b – c). The nonhydrostatic geoid height variations (up to 19 meters) are small compared to the observed topographic anomalies of hundreds of meters, suggesting a high degree of compensation appropriate to a body that has warm ice at depth.
Additional Information
© 2010 American Association for the Advancement of Science. Received 28 September 2009; accepted 5 January 2010. The work of L.I., P.R., and P.T. was funded in part by the Italian Space Agency. The work of N.J.R., R.A.J., J.W.A., and S.W.A. was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. D.J.S. acknowledges support from NASA's planetary geology and geophysics program.Additional details
- Eprint ID
- 17859
- DOI
- 10.1126/science.1182583
- Resolver ID
- CaltechAUTHORS:20100406-090117961
- Agenzia Spaziale Italiana (ASI)
- NASA
- Created
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2010-04-21Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences