Internal structure of asteroids is one of the missing direct observables to date, as only indirect indications can be obtained by asteroid density estimation.
Laboratory impact experiments and numerical modelling can provide further understanding of the way asteroids are shattered and recombine to form gravitational aggregates. The structure formed in post-impact re-accumulation is therefore related to the original impact process.

On the one hand, the analysis of estimated macroporosity of asteroids, combined with numerical simulations, provides clues for understanding the collisional process in different asteroid types. On the other hand, statistics of collisions in the asteroid belt can -in turn- provide information on the internal structure of gravitational aggregates.
Space missions to sound asteroid interiors are compelling in the near future to understand asteroid interiors and provide main quantitative evidence on the fragmentation process itself.

In the absence of such missions, numerical simulations of the post-impact process are the only way to try and understand how such small bodies where formed.

Our group is very active in this field and has started projects to study this phenomenon. The first low-resolution model is able to account for the formation of contact binary asteroids (see ‘Research/Recent papers’).