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Size and shape of Saturn's moon Titan

December 1, 2011

Cassini observations show that Saturn’s moon Titan is slightly oblate. A fourth-order spherical harmonic expansion yields north polar, south polar, and mean equatorial radii of 2574.32 ± 0.05 kilometers (km), 2574.36 ± 0.03 km, and 2574.91 ± 0.11 km, respectively; its mean radius is 2574.73 ± 0.09 km. Titan’s shape approximates a hydrostatic, synchronously rotating triaxial ellipsoid but is best fit by such a body orbiting closer to Saturn than Titan presently does. Titan’s lack of high relief implies that most—but not all—of the surface features observed with the Cassini imaging subsystem and synthetic aperture radar are uncorrelated with topography and elevation. Titan’s depressed polar radii suggest that a constant geopotential hydrocarbon table could explain the confinement of the hydrocarbon lakes to high latitudes.

Citation Information

Publication Year 2009
Title Size and shape of Saturn's moon Titan
DOI 10.1126/science.1168905
Authors Howard A. Zebker, Bryan Stiles, Scott Hensley, Ralph Lorenz, Randolph L. Kirk, Jonathan Lunine
Publication Type Article
Publication Subtype Journal Article
Series Title Science
Index ID 70003641
Record Source USGS Publications Warehouse
USGS Organization Astrogeology Science Center

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