Due to its relatively large eccentricity and proximity to the Sun, Mercury's orbital motion provides one of the best solar-system tests of relativistic gravity. We emphasize the number of feasible relativistic gravity tests that can be performed within the context of the parameterized weak field and slow motion approximation - a usefulframework for testing modern gravitational theories in the solar system. We discuss a new approximation method, which includes two Eddington parameters $(\gamma,\beta)$, proposed for construction of the relativistic equations of motion of extended bodies. Within the present accuracy of radio measurements, we discuss the generalized Fermi-normal-like proper reference frame which is defined in the immediate vicinity of the extended compact bodies. Based on the Hermean-centric equations of motion of the spacecraft around the planet Mercury, we suggest a new test of the Strong Equivalence Principle. The corresponding experiment could be performed with the future {\it Mercury Orbiter} mission scheduled by the European Space Agency ({\small ESA}) for launch between 2006 and 2016. We discuss other relativistic effects including the perihelion advance, redshift and geodetic precession of the orbiter's orbital plane about Mercury. (Refer to PDF file for exact formulas.)

Publication Date



Also archived at: arXiv:gr-qc/9606028 v1 13 Jun 1996 SGT acknowledges the support by the National Research Council of the USA. The research described in this paper was carried out by the Jet Propulsion Laboratory, California Institute of Technology, and was sponsored by the Ultraviolet, Visible, and Gravitational Astrophysics Research and Analysis Program through an agreement with the National Aeronautics and Space Administration. Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.

Document Type


Department, Program, or Center

School of Physics and Astronomy (COS)


RIT – Main Campus