 This may be alleviated if Gaspra is a porous body or started with a large regolith, but one has to explain how the original regolith appeared.A possible resolution of the issue may be that Gaspra obtained a regolith during the Flora-family forming impact that also created Gaspra itself.Secondly, it has been estimated that the matter ejected by all the craters would be only enough to cover Gaspra with 10 m of regolith.