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).