Gravity Field, Shape, and Moment of Inertia of Titan

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, im...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 2010-03, Vol.327 (5971), p.1367-1369
Main Authors: Iess, Luciano, Rappaport, Nicole J, Jacobson, Robert A, Racioppa, Paolo, Stevenson, David J, Tortora, Paolo, Armstrong, John W, Asmar, Sami W
Format: Article
Language:English
Subjects:
Astronomy
Astrophysics
Chemistry
Ellipsoids
Extraterrestrial Environment
Geoids
Gravitation
Gravitational fields
Gravity
Hydrostatics
Ice
Moments of inertia
Moons
Rotation
Saturn
Saturnian satellites
Spacecraft
Water
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.1182583