Maps of secular resonances in the NEO region

TL;DR

This paper maps the locations of secular resonances affecting near-Earth objects (NEOs) within the NEO region, using a semi-analytical model capable of handling high eccentricities and orbit crossings, and validates the results with numerical simulations.

Contribution

Introduces a semi-analytical method to accurately locate secular resonances in the NEO region for high eccentricities, improving upon previous methods.

Findings

Secular resonances are located well inside the NEO region.

The method's predictions align closely with full numerical N-body simulations.

Provides insights into potential dynamical pathways influenced by secular resonances.

Abstract

Context. From numerical simulations, it is known that some secular resonances may affect the motion of near-Earth objects (NEOs). However, the specific location of the secular resonance inside the NEO region is not fully known, because the methods previously used to predict their location can not be used for highly eccentric orbits and when the NEOs cross the orbits of the planets. Aims. In this paper, we aim to map the secular resonances with the planets from Venus to Saturn in the NEO region, even for high values of the eccentricity. Methods. We used an averaged semi-analytical model that can deal with orbit crossing singularities for the computation of the secular dynamics of NEOs, from which we can obtain suitable proper elements and proper frequencies. Then, we computed the proper frequencies over a uniform grid in the proper elements space. Secular resonances are thus located by the level curves corresponding to the proper frequencies of the planets. Results. We determined the location of the secular resonances with the planets from Venus to Saturn, showing that they appear well inside the NEO region. By using full numerical N-body simulations we also showed that the location predicted by our method is fairly accurate. Finally, we provided some indications about possible dynamical paths inside the NEO region, due to the presence of secular resonances.