Level curve of the Hamiltonian from Eq. (7). Orbital plane elements will follow the solid lines. One can distinguish four different kinds of equilibrium: one for retrograde orbits, two for polar orbits, and the one we are interested in, for relatively low inclination. The latter gives us Ω = Ω_⊙ and both ascending nodes of Iapetus and Titan oscillate around it. Equation (12) and Table 2 give an inclination of the local Laplace plane of Titan around 0.62°.