The evolution of asteroids as meteorite parent-bodies

The hypothesis that the asteroid belt is the source region for nearly all meteorites, remains viable and there is no compelling reason to ascribe any meteorites to cometary origin. On the other hand, uncertainties about the true composition of the larger S type asteroids and difficulties in finding plausible main-belt source-bodies for the ordinary chondrites leave room open for further speculation on this question. The scenario for the evolution of asteroids, based on collisional models of two distinct populations of different physical properties, is being criticized and refined. It remains uncertain whether this approach will ultimately prove to be the correct interpretation of the collisional evolution of asteroids.