INERTIA OF ANY POLYHEDRON

Simple formulae are given for the surface area, volume, center of mass , moments of inertia, and principal axes of any homogeneous polyhedron . These can easily be combined with algorithms for the gravitational h eld of such polyhedra. A FORTRAN version of our code (available from t he author) is used to compare digital models of Phobos at different re solutions. The results indicate that a surface resolution of about 10 degrees is adequate to characterize the inertial properties of a small satellite or asteroid within a few percent, comparable to the systema tic uncertainty for Phobos. This accuracy scales as the square of the resolution. (C) 1996 Academic Press, Inc.