PT  - JOURNAL ARTICLE
AU  - Zebker, Howard A.
AU  - Stiles, Bryan
AU  - Hensley, Scott
AU  - Lorenz, Ralph
AU  - Kirk, Randolph L.
AU  - Lunine, Jonathan
TI  - Size and Shape of Saturn's Moon Titan
AID  - 10.1126/science.1168905
DP  - 2009 May 15
TA  - Science
PG  - 921--923
VI  - 324
IP  - 5929
4099  - http://science.sciencemag.org/content/324/5929/921.short
4100  - http://science.sciencemag.org/content/324/5929/921.full
SO  - Science2009 May 15; 324
AB  - 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.