Motion of Iapetus plane over 10 000 years. Both the inclination and the longitude of the ascending node oscillate around the fixed values of the Laplace plane with a period of around 3200 years. Here, and for the rest of this work, the reference plane is the equator of Saturn. The figure comes from a simulation done with all the major satellites of Saturn (Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion, Iapetus), the Sun, and the effect of the flattening of Saturn. The angular elements of the Laplace plane are approximately 15° for the inclination and 225° for the ascending node. The initial conditions are those of the J2000 epoch taken from JPL ephemeris, Horizon (SAT 389.14).