  One of the most well-known tests of General Relativity (GR) results from
combining measurements of the anomalous precession of the orbit of Mercury with
a determination of the gravitational quadrupole moment of the Sun J_2. The
latter can be done by inference from an integral relation between J_2 and the
solar internal rotation. New observational data of high quality obtained from
the Solar Heliospheric Satellite (SoHO) and from the Global Oscillations
Network Group (GONG), allow the determination of the internal rotation velocity
of the Sun as a function of radius and latitude with unprecedented spatial
resolution and accuracy. As a consequence, a number of global properties of the
Sun can also be determined with much higher accuracy, notably the gravitational
quadrupole moment of the Sun. The anomalous precession of the orbit of Mercury
is primarily due to GR effects but there are classical corrections the largest
of which is that due to J_2. It is shown here that the data are currently
consistent with the predictions of GR.
