The link between the shape of the Earth and stress is studied without any a priori rheological hypothesis. The external gravity potentiel is expressed u p t o s e cond order as a function of lateral variations of stress. The inversion of potential and topography data is carried out, up to degree 360 for the Earth and degree 70 for the Moon, minimizing the deviatoric stress. The Earth's crustal thickness, which is the best determined quantity, is found to be more i m p ortant below reliefs, where the tectonic state is in vertical compression. Compilations of `moho' seismic depths conrm our results. Positive mass anomalies under major basins of the Moon are c l e arly visible down to great depth.