The Motion of Celestial Bodies


The history of celestial mechanics is first briefly surveyed, identifying the major contributors and their contributions. The Ptolemaic and Copernican world models, Kepler’s laws of planetary motion and Newton’s laws of universal gravity are presented. It is shown that the orbit of a body moving under the gravitational attraction of another body can be represented by a conic section. The six orbital elements are defined, and it is indicated how they can be determined from observed positions of the body on the sky. Some special cases, permitting exact solutions of the motion of three gravitating bodies, are also treated. With two-body motion as a first approximation, the perturbing effects of other bodies are next derived and applied to the motions of planets, satellites, asteroids and ring particles. The main effects of the Earth’s oblateness on the motions of artificial satellites are explained, and trajectories for sending a space probe from one planet to another are shown. The influences of gravitational tides and nongravitational forces due to solar radiation and gas drag are also treated. Finally, the long-term evolution and stability of the Solar System are briefly discussed.

Cite this paper

@inproceedings{Aksnes2011TheMO, title={The Motion of Celestial Bodies}, author={Kaare Aksnes}, year={2011} }