The hydrostatic equilibrium and its implications on the mechanical properties of planets

Abstract

Under the hypothesis of hydrostatic equilibrium the
planets of the solar system are represented on the plane (J"2, w2 a?/MG)
(J2 = second term of the gravitational potential, w = rotation rate of the
planet, a — equatorial radius, M — mass of the planet, G = gravitational
constant). Since the points representing the planets lie on a straight line
it is possible to obtain informations on the giration moment and the moment
of inertia of Uranus and Pluto.