Asteroid Deflection by Means of Electromagnetic Forces during an Earth Fly-By
Sanjurjo-Rivo, Manuel; Peláez, J.
Universidad Politécnica de Madrid

In recent years, substantial efforts have been carried on in the sake of avoiding a possible impact of a threatening object on the Earth. New technologies have been suggested in this field, investigating the utilization of innovative applications for this purpose. In this context, this paper is devoted to take the most of the fact that, during an Earth fly-by, there will be several distinct forces acting on an asteroid due to the interaction with the Earth magnetic field. Among these interactions, this paper is focused on the Lorentz force, assessing under what assumptions and conditions it can provide an effective deflection of the asteroid orbit.

Concerning this study, three different scenarios are devised. Firstly, an electrostatically charged asteroid evolving under the effect of the Lorentz force, supposing a fixed charge during the fly-by. The effect of this perturbation force on the orbit changes is analyzed in terms of the charge and the initial characteristics of the orbit. Secondly, it will be assumed that the asteroid is conductive and can operate as a electrodynamic tether, that is, the magnetic field inducts an electric field which force the charge motion along it. Here, it will be presupposed that it is possible to maintain a steady current along the asteroid providing the necessary electric contact with the environment even if this aspect could be an actual limiting factor. Finally, the utilization of electrodynamic tethers is considered as a thruster option in close encounter events. Since these devices require a plasma environment for an adequate performance, their operation is restricted to the ionosphere from a practical point of view.

In summary, this paper is devoted to assess the feasibility of using the Lorentz force for deflecting asteroids orbits providing for this purpose estimations of the possible effects of the electromagnetic interactions with the Earth magnetic field.