Thework described in this has somewhat erratically,over monograph grown, of than a more interest inthe was firstaroused period thirty My subject years. thebeautiful and inBroucke.'sthesis also by see computations drawings (1963; Broucke where familiesof orbits in the restricted three 1968), periodic body for the Earth Moon ratio = were mass problem investigated (/.I 0.012155). These that natural for the existence ofthe a explanation drawingssuggested observed familiesand for the found the of orbits could be shapes perhaps by to the limit + 0. a recourse y As first it a to as as step, appeared catalog completely possible necessary the orbits obtained in this limit. orbits of the first generaiing Generating hadbeen studied andother authors. Poincar6 specZes by (1892) Surprisingly, the two other had been Orbits ofthe however, species apparently neglected. second orbits with or consecutive a species, collisions, present comparatively the ofthe simple problem, only two body problem; no using equations yet had been done.An ofthe systematic ever constituent arcs study inventory was inH6non presented (1968).Also little work had been done on farmlies of orbits of the third very to Hill's A numerical species, was corresponding problem. investigation pub lished inR6non (1969).
