GRAVITATIONAL COEFFICIENTS AND INTERNAL STRUCTURES OF THE ICY GALILEAN SATELLITES - AN ASSESSMENT OF THE GALILEO ORBITER MISSION

Simulated radio tracking data from one flyby of Europa, two flybys of Ganymede, and two flybys of Callisto by the Galileo Orbiter yield esti mates of the standard errors in the gravitational coefficient J(2) of 44, 8.5, and 12 (in units of 10(-6)) for Europa, Ganymede, and Callist o, respectively; errors in C-22 (in units of 10(-6)) are 12, 1.7, and 2.1. These errors are sufficiently small that the values of J(2) and C -22 to be measured by Galileo should suffice to determine if the ice a nd rock in the satellite interiors are uniformly mixed or separated, s o long as the bodies are in hydrostatic equilibrium. (C) 1994 Academic Press, Inc.