  The local curvature of the space produced by the Sun causes not only the
perihelion precession of Mercury's elliptical orbit, but also the variations of
the whole orbit, in comparison with those predicted by the Newtonian theory of
gravitation. Calculations show that the gravitational major-axis contraction of
the Mercury's elliptical orbit is 1.3 kilometers which can be confirmed by the
present astronomical distance measurement technology.
