A. Milani and G.F. Gronchi
A generalization of the averaging principle for planet-crossing
orbits is given, together with an algorithm computing the solutions
of the corresponding averaged equations. This allows us to define
proper frequencies and proper elements for planet-crossing objects
with arbitrary semimajor axis, eccentricity and inclination, in the
approximation neglecting the eccentricities and the inclinations of
the planetary orbits.
minor planets - comets - celestial mechanics
