Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8135915 | Icarus | 2016 | 10 Pages |
Abstract
The observed excess J2 (gravity oblateness) was investigated using a combined analysis of gravity and topography, under different plausible geophysical assumptions. The observed gravity is consistent with that generated by the observed shape for an undifferentiated (uniform density) body. However, because the surface is more likely to be water ice, a two-layer model may be a better approximation. In this case, and assuming a mantle density of 920Â kg/m3, some 1-3Â km of excess core oblateness is consistent with the observed gravity. A wide range of moments of inertia is allowed, but models with low moments of inertia (i.e., more differentiation) require greater magnitudes of excess core topography to satisfy the observations.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
Paolo Tortora, Marco Zannoni, Doug Hemingway, Francis Nimmo, Robert A. Jacobson, Luciano Iess, Marzia Parisi,