THE GRAVITATIONAL-FIELD OF DEIMOS

Deimos may be largely uniform in density. We find here the gravitation al field of Deimos and its moments of inertia from the moon's shape an d an assumed uniform density distribution, From these data we compute the expected orientation, The orientation of the model Deimos relative to Mars agrees with that observed to within the observation uncertain ties (a few degrees), Hence Deimos may be homogeneous and not have sig nificant density variations in its interior, We also find that the sph erical harmonic coefficient J(2) is about 0.108 for the model, so that Deimos is about as gravitationally flattened as Phobos, whose J(2) is about 0.105. (C) 1995 Academic Press, Inc.