Publication Date:
2009-04-04
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zebker, Howard A -- Stiles, Bryan -- Hensley, Scott -- Lorenz, Ralph -- Kirk, Randolph L -- Lunine, Jonathan -- New York, N.Y. -- Science. 2009 May 15;324(5929):921-3. doi: 10.1126/science.1168905. Epub 2009 Apr 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geophysics, Stanford University, Stanford, CA 94305, USA. zebker@stanford.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19342551" target="_blank"〉PubMed〈/a〉
Keywords:
Extraterrestrial Environment
;
Hydrocarbons
;
*Saturn
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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