Paper No. 12-4
Presentation Time: 8:00 AM-12:00 PM
GREEN, Michael D., GAGE, Mark, JENKINSON, Garrett, and MAKHNI, Melvin, Science, School, 1895 Saint Edwards Drive, Vero Beach, FL 32963,

A simple mathematical model is developed to facilitate estimates of planetary and satellite core radii. Using estimates of total mass, bulk density, and relevant material (metal, rock, ice) densities derived from spacecraft data and straight forward geologic reasoning, a planetís core dimensions can be reasonably constrained. The model uses two components (core and mantle) which can easily accommodate more complex stratified situations. After demonstrating the efficacy of the technique for Earth, estimates for all planets of the inner solar system are made which fall within published ranges. Applications to satellites of the outer system, especially Ganymede, yield results which have implications for models of magnetic fields generated by rheologically active metal cores. For instance, we argue that Ganymedeís core radius of approxitely 750 km or 25% of its equatorial radius is too small to accommodate an active metal core. We believe that this model is an excellent tool for making first-order approximations of planetary structure and as a teaching tool.

2002 Denver Annual Meeting (October 27-30, 2002)
Session No. 12--Booth# 90
Planetary Geology (Posters)
Colorado Convention Center: Exhibit Hall
8:00 AM-12:00 PM, Sunday, October 27, 2002

© Copyright 2002 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.