The problem of the cosmogony of the solar system has long occupied a central position in astronomical research. The origin of comets plays a substantial role in the solution to this problem. It is therefore necessary to study in detail the “original” and “future” orbits of the comets with nearly parabolic orbits and to examine in particular the great orbical changes that take place when comets pass within the spheres of action of the giant planets.
In the U S.S.R. — especially at the Institute for Theoretical Astronomy (I.T.A.) in Leningrad — considerable attention is paid to investigations of this type. In this respect it is useful to refer to IAU Symposium No. 45, organized in Leningrad in 1970, and in particular to the introductory report by Chebotarev (1972)