Impact induced damage beneath craters

Ackermann et al. (1975) described the subsurface structure of Meteor Crater and identified a fractured rock zone extending to about 1 km deep. The dep th of the fractured/damage zone can be used to extract information about th e impact cratering process. We impacted rock samples (San Marcos gabbro) in the laboratory and imaged the damage structure using both dicing and tomog raphy methods. We propose a simple model to describe the damage zone depth based on the laboratory measurements. The model agrees well with other meth ods for the estimation of the projectile size of Meteor Crater and it may b e used for estimates of damage around craters of other planets and moons.