Shapes of asteroids compared with fragments from hypervelocity impact experiments

Light-curve observations have shown that most asteroids are non-axially symmetrical in shape, probably as a result of fragmentation undergone by objects with negligible gravitational binding. The authors report here results from hypervelocity experiments performed at ≡10 km s-1 against free-falling bodies. They found that, regardless of the very different experimental conditions, the shape distribution obtained is in good agreement with that of the main-belt asteroids of diameter smaller than ≡100 km. This distribution is not consistent with either the symmetrical shapes of the gravity-dominated asteroids, or the elongated Apollo-Amor objects.