Chaos in some young asteroid families
  Asteroid families are groups of minor planets that have a common origin in breakup events. The very young compact asteroid clusters are the natural laboratory to study resonance related chaotic and nonlinear dynamics. The present dynamical configurations and evolution of asteroid associations strongly depends on their ages. In present paper we allocate subclass of very young asteroid families (younger than 1 Myr). We show that resonance-related chaos can play a very important role in dynamics of very young asteroid families. In case of Datura family chaos may be explained by high order mean motion resonance 9:16 with Mars. In case Hobson family chaos is affected by secular resonance. In other considered cases (Kapbos cluster and Lucascavin cluster) origin of chaotic behavior is still unknown. The effect of resonance is very selective in all cases: we see very stable orbits in the vicinity of chaotic ones. In the high order resonance transfer from initial to final orbit take place by temporary capture in exact resonance. The large asteroids (Ceres, Vesta) can made significant effect on dynamic of small bodies in resonance. In some cases (as for Datura and Lucascavin family), their perturbations can extend area of chaotic motion. 
Alexey Rosaev, Eva Plavalova
astro-ph.EP