ON THE HISTORY OF THE SLINGSHOT EFFECT AND COMETARY ORBITS

摘要

The gravity-assist effect that now plays such an important role in the applications to modern space probes is essentially not any different from the planetary perturbations (mainly Jupiter) of nearby comets. Scientists have been fascinated with comets for a very long time and there is also an abundant literature source on comets in the last two centuries. Some of it is on the origin of comets and some on the capture of escape of comets. In general, all of the literature deals in one way or another with the effect that Jupiter has on the cometary orbits, especially on their energy and semi-major axis a. Many formulas exist in the old literature for the Δ (1/a) of a comet during its close encounter with Jupiter. Some of these formulas are identical to the modern formulas that are now being used. We believe that it is fair to say, for instance, that in the middle of the nineteenth century, the French astronomer, Leverrier, understood all of the fine details of the gravity-assist concept as well as we do now. Actually, Laplace had a detailed chapter on the gravity assist in his famous textbook in the late seventeen hundreds, while Tisserand had a similar detailed chapter in his book in the late eighteen hundreds. Because of these reasons, we briefly summarize some of the more important articles on the gravity effect on comets by Jupiter and on cometary perturbations in general. We essentially follow a chronological order, beginning with Laplace, all the way up to some of the recent publications. We specifically mention those that seem to have concrete information on the gravity-assist phenomenon.