The origin of chaos in the Solar System through computer algebra

Vol. 662
1. Letters to the Editor

The origin of chaos in the Solar System through computer algebra

We have known for more than 30 years that the Solar System is chaotic. This Letter goes further in identifying the origin of chaos. For that, the authors expand the equations that rule the motion of the planets using their own algebraic manipulator, TRIP. These expansions, which consist of tens of thousands of terms, permit them to isolate the different contributions in the equations, and in particular the resonances between the fundamental frequencies of the system. Then these different contributions are confronted with a chaos indicator, the finite-time maximum Lyapunov exponent (FT-MLE). This numerical study emphasizes the secular resonances that are responsible for chaos, offering different possible orbital configurations for the planets of the inner Solar System over the ages.