A Disk of Scattered Icy Objects and the Origin of Jupiter-Family Comets

TLDR

The disk formed in the simulations by encounters with Neptune during the early evolution of the outer solar system. Orbital integrations over 4 billion years produced a scattered disk beyond Neptune, distinct from the Kuiper belt by higher eccentricities and inclinations, with about 1 % of particles surviving to the present and a population of ~6 × 10⁸ objects sufficient to supply all observed Jupiter‑family comets, while two recently discovered bodies match the predicted orbits, indicating they are the only identified members.

Abstract

Orbital integrations carried out for 4 billion years produced a disk of scattered objects beyond the orbit of Neptune. Objects in this disk can be distinguished from Kuiper belt objects by a greater range of eccentricities and inclinations. This disk was formed in the simulations by encounters with Neptune during the early evolution of the outer solar system. After particles first encountered Neptune, the simulations show that about 1 percent of the particles survive in this disk for the age of the solar system. A disk currently containing as few as ∼6 × 10 8 objects could supply all of the observed Jupiter-family comets. Two recently discovered objects, 1996 RQ 20 and 1996 TL 66 , have orbital elements similar to those predicted for objects in this disk, suggesting that they are thus far the only members of this disk to be identified.