This book focuses on the impact dynamics and cratering of soft matter to describe its
importance difficulty and wide applicability to planetary-related problems. A comprehensive
introduction to the dimensional analysis and constitutive laws that are necessary to discuss
impact mechanics and cratering is first provided. Then particular coverage is given to the
impact of granular matter which is one of the most crucial constituents for geophysics. While
granular matter shows both solid-like and fluid-like behaviors neither solid nor fluid
dynamics is sufficient to fully understand the physics of granular matter. In order to reveal
its fundamental properties extensive impact tests have been carried out recently. The author
reveals the findings of these recent studies as well as what remains unsolved in terms of
impact dynamics. Impact crater morphology with various soft matter impacts also is discussed
intensively. Various experimental and observational results up to the recent Itokawa asteroid's
terrain and nanocrater are reviewed and explained mainly by dimensional analysis. The author
discusses perspectives of the relation between soft matter physics and planetary science
because it is an important step towards unifying physics and planetary science in both of
which fields crater morphology has been studied independently.
