Let us assume the mass density is uniform. Since "δ" is much smaller than "A", the deformation can be treated as a thin shell added to the mass of the Earth, where the shell has a surface mass density "ρ" "δ" (and can also be negative), with "ρ" being the mass density (if mass density is not uniform, then the change of shape of the planet creates differences in mass distribution in all depth, and this has to be taken into account as well). Since the gravitation potential has the same form as the electric potential, this is a simple problem in electrostatics. For the analogous electrostatic problem, the potential created by the shell has the form: