Constraining asteroid dynamical models using GAIA data

GAIA is expected to greatly enhance our knowledge on the orbital, spin-state, spectral and size distribution of individual asteroids and asteroid families. Dynamical models, incorporating resonant phenomena and thermal (Yarkovsky/YORP) effects, can be used to understand the observations, in particular the orbital, size-frequency and spin-axis distributions in families and groups. Conversely, the GAIA data can be used to appropriately modify/constrain our models. Such work will necessarily involve an optimization procedure, for which a large number of dynamical experiments will typically be needed; this is clearly a limiting factor. We present here a preliminary version of a statistical model that describes asteroid transport due to gravitational perturbations in the 3-D space of proper elements, coupled with Yarkovsky drift effects. Computationally, the model is very efficient for studying the long-term evolution of large ensembles of asteroids (e.g. families). Thus, given a “final” distribution of orbits, spins and sizes, our model could be used in an iterative fashion, to derive e.g. an optimal guess of the initial ejection velocity field in a family-forming event.