The depletion of the Hecuba gap vs the long-lasting Hilda group

This paper presents a comparative analysis of the 2/1 and 3/2 asteroidal re sonances based on several analytical and numerical tools. The frequency map analysis was used to obtain a refined estimation of the chaotic transport. Fourier and wavelet analyses were used to construct the web of inner reson ances and showed that they are the seat of the strongly unstable motion obs erved in the numerical simulations. The most regular regions in both resona nces were classified. A fast symplectic mapping allowed a number of direct runs over 10(8) years of the orbits initially in these regions. The stabili ty of orbits over the age of the solar system was discussed and compared to the distribution of the observed asteroids in both resonances. (C) 1998 El sevier Science Ltd. All rights reserved.