https://doi.org/10.1140/epjs/s11734-025-01986-1
Regular Article
Equilibrium points and surface dynamics about comet 67P/Churyumov–Gerasimenko
Department of Mathematics, School of Engineering and Sciences, São Paulo State University (UNESP), Guaratinguetá, SP, Brazil
a
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Received:
30
April
2025
Accepted:
20
September
2025
Published online:
1
October
2025
Abstract
Small bodies in our Solar System are considered remnants of their early formation. Studying their physical and dynamic properties can provide insights into their evolution, stability, and origin. ESA’s Rosetta mission successfully landed and studied comet Churyumov–Gerasimenko (67P) for approximately two years. In this work, the aim is to analyze the surface and orbital dynamics of comet 67P in detail, using a suitable 3-D polyhedral shape model. We applied the polyhedron method to calculate dynamic surface characteristics, including geometric height, surface tilt, surface slopes, geopotential surface, acceleration surface, escape speed, equilibrium points, and zero-velocity curves. The results show that the gravitational potential is predominant on the comet’s surface due to its slow rotation. The escape speed has the maximum value in the Hapi region (the comet’s neck). The surface slopes were analyzed to predict possible regions of particle motion and accumulation. The results show that most regions of the comet’s surface have low slopes. Furthermore, we analyzed the slopes under the effects of third-body gravitational and solar radiation pressure perturbations. Our results showed that the effects of third-body perturbations do not significantly affect the global behavior of slopes. Meanwhile, the solar radiation pressure does not significantly affect particles across the surface of comet 67P with sizes 
cm at apocenter and 
cm at pericenter. We also identified four equilibrium points around comet 67P and one equilibrium point inside the body, where points E
and E
are linearly stable. In addition, we approximated the shape of comet 67P using the simplified dipole segment model to study its dynamics, employing parameters derived from its 3-D polyhedral shape model. We found 12 families of planar symmetric periodic orbits around the body.
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© The Author(s), under exclusive licence to EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
