P. J. MESSAGE University of Liverpool The papers which comprise this volume were presented at Colloquium No. 41 of the International Astronimical Union, which was held in Cambridge, England, from the 17th to the 19th of August, 1976, and had as its subject 'Dynamics of Planets and Satellites and Theories of their Motion'. The Colloquium was held just prior to the XVIth General Assembly of the Union (which was held from 24th August to 2nd September, in Grenoble, France) to provide an opportunity for the presentation of research papers on a number of active and lively branches of Celestial Mechanics to a gathering of experts in the field, and for the stimulus of discussion of research problems of interest to participants. A number of papers testify to the progress being made in General Planetary Theory, the theories of motion of the minor planets, the Moon, and the satellites of Jupiter and Saturn, and to significant advances in both the general and restricted gravitational problems of three bodies. The Organizing Committee of the Colloquium was comprised of J. Chapront, R. L. Duncombe, J. Hadjidemetriou, Y. Kozai, B. Morando, J. Schubart, V. Szebehely, and P. J. Message (Chairman). The local Organizer was D. C. Heggie, to whose tireless efforts the success of the arrangements is due. IX LIST OF PARTICIPANTS N. Abu-el-Ata, Bureau des Longitudes, 77 Avenue Denfert Rochereau, 75014 Paris, France K. Aksnes, Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, U. S. A.

Inhalt

I. Planetary Theory and Analytical Methods.- Planetary Theories and Observational Data.- Correspondances entre une théorie générale planétaire en variables elliptiques et la théorie classique de Le Verrier.- Mathematical Results of the General Planetary Theory in Rectangular Coordinates.- Construction of Planetary Theory by Iterative Procedure.- Qualitative Dynamics of the Sun-Jupiter-Saturn System.- A New Approach for the Construction of Long - Periodic Perturbations.- Construction d'une théorie planétaire au troisième ordre des masses.- Discussion sur les résultats de théories planétaires.- Relation of a Contracting Earth to the Apparent Accelerations of the Sun and Moon (Abstract).- The Asteroidal Planet as the Origin of Comets.- Comets and the Missing Planet.- Mac Revisited: Mechanised Algebraic Operations on Fourth Generation Computers (Abstract).- II. Lunar Theory and Minor Planet Motions.- Contribution a 1'étude des perturbations planétaires de la Lune.- Hamiltonian Theory of the Libration of the Moon.- New Results on the Commensurability Cases of the Problem Sun-Jupiter-Asteroid.- A Theory of the Trojan Asteroids (Abstract).- III. Numerical and Other Techniques.- Stabilization by Making use of a Generalized Hamiltonian Variational Formalism.- A Special Perturbation Method: m-Fold Runge-Kutta (Abstract).- Numerical Integration of Nearly-Hamiltonian Systems.- On the Solution of the Exterior Boundary Value Problem with the Aid of Series (Abstract).- A Note on the Development of the Reciprocal Distance in Planetary Theory (Abstract).- IV. Satellites of Jupiter and Saturn, and Artificial Satellites.- An Application of the Stroboscopic Method.- New Formulation of De Sitter's Theory of Motion for Jupiter I-IV. I: Equations of Motion and the Disturbing Function.- Theory of Motion of Jupiter's Galilean Satellites (Abstract).- A Second-Order Theory of the Galilean Satellites of Jupiter.- Solar Perturbations in Saturnian Satellite Motions and Iapetus-Titan Interactions (Abstract).- Improvement of Orbits of Satellites of Saturn using Photographic Observations (Abstract).- New Orbits for Enceladus and Dione Based on the Photographic Observations (Abstract).- Long-Periodic Variation of Orbital Elements of a Satellite Perturbed by Discrete Gravity Anomalies (Abstract).- Third-Order Solution of an Artificial-Satellite Theory.- Some Considerations on the Theoretical Determination of the Potential by the Motion of Artificial Satellites in the Plane case (Abstract).- V. Gravitational Problems of Three or More Bodies.- Families of Periodic Planetary-Type Orbits in the N-Body Problem and Their Application to the Solar System.- Perturbations of Critical Mass in the Restricted Three-Body Problem (Abstract).- Gravitational Restricted Three-Body Problem: Existence of Retrograde Satellites at Large Distance.- Displacement of the Lagrange Equilibrium Points in the Restricted Three Body Problem with Rigid Body Satellite.- A New Kind of Periodic Orbit: The Three-Dimensional Asymmetric.- On Asymmetric Periodic Solutions of the Plane Restricted Problem of Three Bodies, and Bifurcations of Families.- Construction de solutions périodiques du problème restreint elliptique par la méthode de Hale.- Orbital Stability in the Elliptic Restricted Three Body Problem.- Resonance in the Restricted Problem of Three Bodies with Short-Period Perturbations in the Elliptic Case.- Periodic Orbits of the First Kind in the Restricted Three Body Problem when the More Massive Primary is an oblate spheroid (Abstract).- Triple Collision as an Unstable Equilibrium (Abstract).- Regions of Escape on the Velocity Ellipsoid for the Planar Three Body Problem.- Index of Names.- Index of Subjects.