  In the present work we show that planetary mean distances can be calculated
with the help of a Schrodinger-type diffusion equation. The obtained results
are shown to agree with the observed orbits of all the planets and of the
asteroid belt in the solar system, with only three empty states. Furthermore,
the equation solutions predict a fundamental orbit at 0.05 AU from solar-type
stars, a result confirmed by recent discoveries. In contrast to other similar
approaches previously presented in the literature, we take into account the
flatness of the solar system, by considering the flat solutions of the
Schrodinger-type equation. The model has just one input parameter, given by the
mean distance of Mercury.
