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tokens: Results of our simulations indicated the following: 1. Considering the current range of impact velocities in the asteroid belt, the depth of an impact crater is only slightly larger than 10 m even when the target is assumed to be of the softest material. This suggests that if the activation of MBCs is due to the sublimation of water–ice, ice must be buried in the top few meters of the object. The latter is consistent with the model by Schörghofer ( 2008 ), who showed that a layer of dust with a thickness of only a few tens of centimeters can prevent water–ice in asteroids from sublimating for the age of the solar system; 2. A substantial amount of ice may be exposed on the inner surface of an impact crater, contributing to the activation of an MBC. The size and therefore the inner area of a crater is larger for targets with a higher water-mass fraction; 3. Some of the ejected material may be re-accreted when the impact velocities are low (e.g., ≲100 m s −1 ), and may contribute to the activation of MBCs. Calculations by Hsieh et al. ( 2004 ) and Hsieh Jewitt ( 2006 ) suggested a very large ice exposure area to account for the activity of MBC 133P/(7968) Elst-Pizzaro. Our simulations indicated that while for an object similar to this MBC, the exposed ices on the bottom and interior surface of an impact crater, combined with the ice re-accreted on the surface of the object may be large enough to account for its activation, in general, due to the small gravity of MBCs, the amount of re-accreted material on the surfaces of these objects is too small to contribute to their activity. The latter implies that the activity of MBCs is most likely due to ice sublimation from multiple impact craters and/or the water content of these bodies are larger than the anticipated 5%, providing more ice in exposed areas for sublimation. Although the simulations presented here portray the impact scenario as a viable mechanism for exposing sub-surface ice to ignite the activity of MBCs, they contain some limiting assumptions. First, we did not consider porosity for our targets. Including porosity is a complicated task that requires developing complex mathematical models. This is currently under development and we expect the results to be ready for publication in the not-so-distant future. However, given the simulations presented here, we do not expect the result to change drastically, even when porosity is included. We considered the target material to be basalt or tuff. However, MBCs are most likely made of carbonaceous chondrites. That means, in order to simulate impact events, the knowledge of the equation of state of this material, as well as the flaw distribution for the fracture model, are required, which are unknown. Our approach, that is, simulating impacts using a very hard (basalt) and a very soft (tuff) target, allows us to portray a general picture of the impact scenario as a mechanism for ice exposure that can be applied to a variety of targets with