The asteroid ring

ABSTRACT The asteroid belt between Mars and Jupiter has some features in common with planetary rings; these include gaps associated with resonances and a tendency for pericenter alignment. While it is tempting to think of the Jupiter-asteroid belt system in terms of satellite-disk interactions, the present low spatial density of the belt limits, for example, the application of the spiral density wave theory, which has achieved some success in explaining the resonant structure of Saturn's rings. However, some authors claim that this process, and some other processes, would have been effective in the belt's early history, if the belt was then both flatter and more massive. It is likely that Jupiter's orbital period was then at least slightly different from the present period. From a statistical analysis of the asteroid orbital period data, we show that the present distribution of asteroids is strongly correlated with the present orbital period of Jupiter (to 1 part in 5000). Furthermore, by analyzing the distribution of orbital eccentricities and inclinations we show that the resonant structure of the belt was formed after the asteroids had dispersed from the near-coplanar disk in which they accreted.