Drift and its mediation in terrestrial orbits

TL;DR

This paper investigates the slow deformation and drift of terrestrial orbits influenced by lunisolar resonances, using Hamiltonian models and chaos indicators to analyze the structure of the action space and the role of KAM tori.

Contribution

It provides high-resolution visualizations of the action space, revealing the influence of KAM tori on orbit drift and offering detailed analysis of initial conditions and their asymptotic behavior.

Findings

Identification of chaotic regions and tori in the action space.

Demonstration of how KAM tori mediate orbital drift.

High-resolution portraits of the phase space structure.

Abstract

The slow deformation of terrestrial orbits in the medium range, subject to lunisolar resonances, is well approximated by a family of Hamiltonian flow with $2.5$ degree-of-freedom. The action variables of the system may experience chaotic variations and large drift that we may quantify. Using variational chaos indicators, we compute high-resolution portraits of the action space. Such refined meshes allow to reveal the existence of tori and structures filling chaotic regions. Our elaborate computations allow us to isolate precise initial conditions near specific zones of interest and study their asymptotic behaviour in time. Borrowing classical techniques of phase- space visualisation, we highlight how the drift is mediated by the complement of the numerically detected KAM tori.