The biological effects of asteroid and comet impacts have been widely viewed as primarily destructive. The role of an impactor in the K/T boundary extinctions has had a particularly important influence on thinking concerning the role of impacts in ecological and biological changes. th During the 10 and final workshop of the ESF IMPACT program during March 2003, we sought to investigate the wider aspects of the involvement of impact events in biological processes, including the beneficial role of these events from the prebiotic through to the ecosystem level. The ESF IMPACT programme (1998-2003) was an interdisciplinary effort that is aimed at understanding impact processes and their effects on the Earth environment, including environmental, geological and biological changes. The IMPACT programme has 15 member states and the activities of the programme range from workshops to short courses on topics such as impact stratigraphy, shock metamorphism, etc. The program has also awarded mobility grants and been involved in the development of teaching aids and numerous publications, including this one.