Short-Period Comets: Primordial Bodies or Collisional Fragments?
Modeling results show that collisions among Edgeworth-Kuiper Belt Objects (EKOs), a vast swarm of small bodies orbiting beyond Neptune, have been a major process affecting this population and its progeny, the short-period comets. Most EKOs larger than about 100 kilometers in diameter survive over the age of the solar system, but at smaller sizes collisional breakup is frequent, producing a cascade of fragments having a power law size-frequency distribution. Collisions are also a plausible mechanism for injecting EKOs 1 to 10 kilometers in diameter into dynamical resonances, where they can be transported into the inner solar system to become short-period comets. The fragmental nature of these comets may explain their physical properties, such as shape, color, and strength.
Farinella
P
P. Farinella, Dipartimento di Matematica, Universita di Pisa, Via Buonarroti 2, 56127 Pisa, Italy. D. R. Davis, Planetary Science Institute, 620 North Sixth Avenue, Tucson, AZ 85705-8331, USA.
Davis
DR