The figure of Phobos
Abstract
A sixth degree and order spherical harmonic expansion was used to model the Phobos figure. This model appears to fit the entire surface to an accuracy of a few hundred meters, except in the region around the large crater Stickney. The model was validated using control points, limbs, terminators, map projections and predicted rotational properties. A for A forced libration amplitude of 0.81 ± 0.5 (1 σ) deg is predicted, matching the observed value of 0.79 deg which supports Phobos having a uniform density distribution to within the uncertainty of the prediction.
 Publication:

Icarus
 Pub Date:
 March 1989
 DOI:
 10.1016/00191035(89)900754
 Bibcode:
 1989Icar...78..169D
 Keywords:

 Astronomical Models;
 Geodesy;
 Phobos;
 Planetary Structure;
 Spherical Harmonics;
 Computational Astrophysics;
 Density Distribution;
 Gravitational Fields;
 Libration;
 Satellite Surfaces;
 Viking Spacecraft;
 MARS;
 SATELLITES;
 PHOBOS;
 MODELS;
 SURFACE;
 HARMONICS;
 DIAGRAMS;
 CALCULATIONS;
 TOPOGRAPHY;
 GRAVITY FIELDS;
 SPACECRAFT OBSERVATIONS;
 PHOTOGRAPHS;
 Lunar and Planetary Exploration; Satellites of Mars