Impact cratering is a fundamental geological process in the solar system. The formation of impact craters is a highly dynamic and complex process that subjects the impacted target rocks to numerous types of deformation. The impact process can be subdivided into three subsequent stages, the contact and compression stage, the excavation stage, and the modification stage. In the first stage extremely high pressures and temperatures occur when the initial shock wave passes through the target rock and projectile and causes widespread shock metamorphism. Rocks are set in motion and the resulting flow field in the target excavates and ejects rock materials (2nd stage). Gravitationally induced mass movements modify the transient crater cavity and lead to simple or complex crater morphologies (3rd stage).
Planetary bodies with solid surfaces are mostly covered by impact craters (e.g. Melosh 1989). This testifies that impact cratering is among the most important geological processes in the solar system. For instance, Mars has more than 300.000 craters larger than 1 km. In contrast, only 188 impact craters have been confirmed on Earth so far (Hergarten & Kenkmann 2015). The permanently changing face of our planet is the obvious reason for this sparse crater record. Understanding the dynamics of impact cratering is essential for unraveling the history of the solar system; though it has also applied aspects: Hypervelocity impacts still pose a threat to human civilization. The 15-m meteorite impact crater, formed 2007 at Carancas, Peru, (Kenkmann et al. 2009) or the encounter of a 19 m bolide that exploded in the atmosphere near Cheljabinsk, Russia on Feb. 15, 2013 (Popova et al. 2013) indicates the continued threat we face from impact events.