Gravity Field of Phobos and its Long Term Variations
The only information of the Phobos gravitational field is the data given by spacecrafts imaging the Phobos surface. The first detailed model of the Phobos boundary topography was established by Turner (197B), based on the Mariner 9 television pictures. Provided that Phobos is a homogeneous body, Sagitov et al. (1981), evaluated the Stokes parameters of the external gravitational field by numerical integration. An independent analytical approach by Martinec et al. (1989) using the spherical harmonic expansion of the Phobos topography checked the earlier results and, in fact, proved Sagitov’s (1981) results. Unfortunately, due to many possible shortcomings of the Turner’s globe, results by Sagitov et al. (1981), as well as, by Burša et al. (1988; cannot be used for the correct representation of the Phobos external gravitational field.
KeywordsGravitational Field Stokes Parameter Spherical Harmonic Expansion Love Number Homogeneous Body
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