Despite their global importance, little is known about the few existing examples of impacts into marine environments and icy targets. They are among the least understood and studied parts of impact crater geology. The icy impacts are also of great importance in understanding the developments of the outer planets and their satellites such as Mars or Europa. Furthermore, the impact mechanisms, crater formation and collapse, melt production and the ejecta distribution are scarcely known for impact on targets other than the "classical" solid silicates of the continental crust. The reaction of water and ice to impacts clearly deserves a more thorough study. The understanding of impact effects and consequences in the case of aqueous hits, soft sediments and icy targets has not been thoroughly explored and comprises the main focus of this book. A number of papers in the field of hypervelocity impacts on ice are included. These cover a review of available literature in the field of laboratory studies of such impacts, large impact structures on Titan, predicting impact cratering on a comet nucleus, and a novel report on the survival of bacteria fired at hypervelocity into icy surfaces. This latter paper is concerned with astrobiology and in particular Panspermia (natural migration of life through space).
Impacts into Marine and Icy Environments.- Biotic Responses to the Mjolnir Meteorite Impact, Barents Sea: Evidence from a Core Drilled within the Crater.- Near-field Erosional Features at the Mjolnir Impact Crater: the Role of Marine Sedimentary Target.- Global Effects of the Chicxulub Impact on Terrestrial Vegetation - Review of the Palynological Record from New Zealand Cretaceous/Tertiary Boundary.- The Neugrund Marine Impact Structure (Gulf of Finland, Estonia).- Structure-filling Sediments of the Wetumpka Marine-target Impact Structure (Alabama, USA).- Krk-breccia, Possible Impact-Crater Fill, Island of Krk in Eastern Adriatic Sea (Croatia).- Did the Puchezh-Katunki Impact Trigger an Extinction?.- Geochemistry of a Langhian Pelagic Marly Limestone Sequence of the Conero Riviera, Ancona (Italy) and the Search for a Ries Impact Signature: A Progress Report.- Titan: A New World Covered in Submarine Craters?.- Estimating Crater Size for Hypervelocity Impacts on Small Icy Bodies (e.g. Comet Nucleus).- Survivability of Bacteria in Hypervelocity Impacts on Ice.- Impact Cratering of Icy and Rocky Targets in Planetary Sciences and in the Laboratory.- Paleomagnetism and 40Ar/39Ar Age Determinations of Impactites from the Ilyinets Structure, Ukraine.- Cathodoluminescence, Electron Microscopy, and Raman Spectroscopy of Experimentally Shock Metamorphosed Zircon Crystals and Naturally Shocked Zircon from the Ries Impact Crater.- A Brief Introduction to Hydrocode Modeling of Impact Cratering.