  We consider, in the framework of General Relativity, the linear approximation
of the gravitational field of the Earth taking into account its mass, its
quadrupole moment, its shape and its diurnal rotation.
  We conclude that in the frame of reference co-moving with the Earth the local
anisotropy of the space is of the order of $10^{-12}-10^{-13}$ and could be
observed.
