Dynamical behaviour of the primitive asteroid belt
Abstract
In this paper we consider the dynamical evolution and orbital stability of objects in the asteroid belt. A simple physical model, including full gravitational perturbations from both giant planets, is used to compute the dynamical evolution of 1000 test particles simulating the primitive asteroids. The criterion of planet crossing (or close approach in the case of resonant objects) is used to reject particles from the simulation. 44 per cent of the particles survived for the whole time-span covered by the numerical integration (~10^9 yr). The 4:1, 3:1 and to a lesser extent the 2:1 Kirkwood gaps are formed in ~10^7 yr of evolution, representing direct numerical evidence about their gravitational origin. We found that the rms eccentricity and inclination of the sample experience a fast increase during the first 10^6 yr. The final rms eccentricity is 0.11, ~60 per cent smaller than the present rms eccentricity (0.17). Nevertheless, the gravitational action of the giant planets suffices to prevent the formation of large objects, allowing catastrophic collisions and the subsequent depletion of material from this zone of the Solar system. The excited eccentricity by Jupiter and Saturn may favour mutual encounters and the further increase of the relative velocities up to their present values.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 1998
- DOI:
- 10.1046/j.1365-8711.1998.01122.x
- Bibcode:
- 1998MNRAS.293..405B
- Keywords:
-
- Asteroid Belts;
- Gravitational Effects;
- Planetary Gravitation;
- Gas Giant Planets;
- Jupiter (Planet);
- Saturn (Planet);
- Astrophysics;
- CELESTIAL MECHANICS;
- STELLAR DYNAMICS;
- MINOR PLANETS;
- ASTEROIDS