When
3:30 p.m., Jan. 19, 2010
Where
Kuiper Space Sciences Building 308
Dr. David Stevenson from Caltech is the scheduled speaker.
The Cassini results for Titan gravity will be presented and interpreted, both for the moment of inertia and its implications for internal structure, and the relationship to the shape of Titan. The degree 2 gravity results suggest that Titan is imperfectly differentiated (i.e., the deepest regions are a mixture of ice and rock), suggesting a long accretion time as has previously been advocated for Callisto. The degree 3 gravity is small suggesting a high level of compensation (isotasy). The gravity discussion will provide an opportunity for presentation of some new theoretical work on the implications of small non-hydrostatic effects on global reorientation (True Polar Wander) and the pitfalls in the traditional Radau-Darwin approach to moment of inertia for Titan and other slowly rotating bodies (e.g., Callisto) though these problems are probably not sufficient to invalidate the claimed failure to fully differentiate.
The Cassini results for Titan gravity will be presented and interpreted, both for the moment of inertia and its implications for internal structure, and the relationship to the shape of Titan. The degree 2 gravity results suggest that Titan is imperfectly differentiated (i.e., the deepest regions are a mixture of ice and rock), suggesting a long accretion time as has previously been advocated for Callisto. The degree 3 gravity is small suggesting a high level of compensation (isotasy). The gravity discussion will provide an opportunity for presentation of some new theoretical work on the implications of small non-hydrostatic effects on global reorientation (True Polar Wander) and the pitfalls in the traditional Radau-Darwin approach to moment of inertia for Titan and other slowly rotating bodies (e.g., Callisto) though these problems are probably not sufficient to invalidate the claimed failure to fully differentiate.