Recent Advances in Modeling Gravity Field of Small Bodies

Small celestial bodies in the Solar system, such as asteroids and comets, have become the key targets in the field of deep space exploration. The exploration of small celestial bodies is of great significance for studying the formation and evolution of the solar system, the origin of life, planetary defense, and the exploitation of space resources. With the continuous development of aerospace technology, the way of small-body exploration has gradually shifted from flyby and orbiting to close-proximity detection methods, such as landing, sampling, and touring. The construction of a high-accuracy gravitational field model in the vicinity of the given small body is crucial to the design and implementation of such close-proximity exploration missions and to the study of dynamics near the small bodies. Thus, this paper first reviews the two-hundred-year history of development of the modeling of gravitational field, and elucidates the basic principles and drawbacks in the different methods. The relationship between the gravitational field near the binary asteroid system and the dynamics of such system is second reviewed. This paper also reviews the techniques for modelling the gravitational interactions in the study of the dynamics of the binary asteroid system. These techniques provide fundamental tools for the binary system mission designs and the study of the formation and evolution of the binaries. Finally, the future research trends are discussed.