Craters and Chaos structures on Europa

Abstract

Chaos structure found on Europa was experimentally reproduced by the impact experiments. Two-layer model composed of water layer covered with thin ice plate was used for the target on the cratering experiments by ice projectile colliding at the velocity from 140 to 400 m/s. We have found three types of impact structures according to the impact conditions, which were simple crater, penetrated hole, and chaos failure. The shock stress propagation in ice and water could be a key process to understand the mechanism creating these different structures.