Today collisions of large celestial bodies are rare events in our solar system. The collision probability, however, is in no case zero, as the impact of the comet Shoemaker Levi 9 onto Jupiter in July 1994 or the Tunguska impact in 1908 show clearly. We are easily inclined to call these impacts disasters, but the perception is relative. The Chicxulub impact 65 Million years ago at the Cretaceous-Tertiary boundary is associated with the extinction of the dinosaurs. However, this event has allowed for the development of "higher" creatures up to mammals, primates, etc.
In the laboratory the extreme situations prevailing during the impact onto a terrestrial body are far beyond being reachable. For a study in the "natural laboratory", the events are too rare. Hence, a computer simulation qualifies for the understanding of the processes of an impact. It allows the estimation of local and global consequences. Further on, certain geological observations and anomalies can be correlated with impact structures. In close cooperation with the DLR Institute of Planetary Research in Berlin, impacts of different projectiles onto terrestrial surfaces or into oceans are simulated. The hydrodynamics of the involved materials is studied and the creation and expansion of condensates of geological relevance is analyzed.
This animation shows the simulated impact of an asteroid into the ocean [animation: Detlef de Niem, Dissertation TU Braunschweig, 2005].
References
de Niem, D., E. Kührt, U. Motschmann, A volume-of-fluid method for simulation of compressible axisymmetric multimaterial-flow, Computer Phys.Comm., 176, 170-190, 2007
de Niem, D., E. Kührt, U. Motschmann, Ejecta range: a simulation study of terrestrial impacts, Planet. Space Sci., 55, 900-914, 2007