Possible long-lived asteroid belts in the inner solar system

Recent years have seen the discovery of several objects in stable orbits in the outer Solar System(1-3); these bodies include objects in the Kuiper be lt (also known as the Kuiper-Edgeworth belt) as well as the Centaurs. Moreo ver, another region of orbital stability has been identified between the or bits of Uranus and Neptune(4). Here we report evidence from numerical simul ations of zones of orbital stability in the inner Solar System. We find tha t there are two possible long-lived belts of asteroids. The first region li es between the Sun and Mercury, in the range 0.09-0.21 astronomical units, where remnant planetesimals may survive for the age of the Solar System pro vided that their radii are greater than similar to 0.1 kilometres, The seco nd region of stability is between Earth and Mars (range 1.08-1.28 astronomi cal units), where a population of bodies that are on circular orbits may su rvive. A search through the catalogues of near-Earth objects reveals an exc ess of asteroids with low eccentricities and inclinations occupying this la tter region: several examples are the recently discovered objects 1996 XB27 , 1998 HG49 and 1998 KG3.