A particle-linkage model for elongated asteroids with three-dimensional mass distribution

Abstract

The goal of the present paper is to develop a simplified model to describe the gravitational fields of elongated asteroids. The proposed model consists of representing an elongated asteroid using a triple-particle-linkage system distributed in the three-dimensional space and it is an extension of previous planar models. A non-linear optimisation method is used to determine the parameters of our model, minimising the errors of all the external equilibrium points with respect to the solutions calculated with a more realistic approach, the Mascon model, which are assumed to give the real values of the system. The model considered in this article is then applied to three real irregular asteroids: 1620 Geographos, 433 Eros, and 243 Ida. The results show that the current triple-particle-linkage three-dimensional model gives better accuracy when compared to the axisymmetric triple-particle-linkage model available in the literature, and provides an advantage in terms of accuracy over the mass point model, while keeping computational time low. This model is also used to carry out simulations to characterise regions with solutions that remain bounded or that escape from around each asteroid under analysis. We investigated initial inclinations of 0○ (direct orbits) and 180○ (retrograde orbits). We considered the gravitational field of the asteroid, the gravitational attraction of the Sun, and the SRP. Our results are then compared to the results obtained using the Mascon gravitational model, based on the polyhedral shape source. We found good agreement between the two models.

Numerical Investigations of the Orbital Dynamics Around a Synchronous Binary System of Asteroids

“…Other works have investigated the dynamics around small irregular bodies using a simplified model given by an homogeneous cube (Liu et al 2011), a simple flat plate (Blesa. 2006), a rotating mass dipole Barbosa Torres dos Santos et al 2017;dos Santos et al 2017), the dipole segment model (Zeng et al 2018), a rotating mass tripole (Lan et al 2017;dos Santos et al 2020;Santos et al 2021), and many others.…”