Physical properties of asteroid Dimorphos as derived from the DART impact

On September 26, 2022, NASA's DART mission successfully impacted Dimorphos, the moon of the binary near-Earth asteroid Didymos. Numerical simulations of the impact were used to determine the surface material properties and structures consistent with observations. The best-matching simulation suggests Dimorphos is weak, with cohesive strength below a few pascals, similar to Ryugu and Bennu. Its bulk density is less than ~2,400 kg m⁻³, with a low volume fraction of boulders (≤40 vol%). These findings support the hypothesis that Dimorphos is a rubble pile formed by rotational mass shedding and reaccumulation from Didymos. The DART impact caused significant global deformation and resurfacing, possibly obscuring a well-defined crater.

S. D. Raducan, M. Jutzi, A. F. Cheng, Y. Zhang, O. Barnouin, G. S. Collins, R. T. Daly, T. M. Davison, C. M. Ernst, T. L. Farnham, F. Ferrari, M. Hirabayashi, K. M. Kumamoto, P. Michel, N. Murdoch, R. Nakano, M. Pajola, A. Rossi, H. F. Agrusa, B. W. Barbee, M. Bruck Syal, N. L. Chabot, E. Dotto, E. G. Fahnestock, P. H. Hasselmann, I. Herreros, S. Ivanovski, J.-Y. Li, A. Lucchetti, R. Luther, J. Ormö, M. Owen, P. Pravec, A. S. Rivkin, C. Q. Robin, P. Sánchez, F. Tusberti, K. Wünnemann, A. Zinzi, E. Mazzotta Epifani, C. Manzoni, B. H. May