GUEST OVERVIEW: Prof. Chandra Wickramasinghe is an astronomer, astrobiologist and co-proponent with the late Sir Fred Hoyle of the theory of cometary panspermia. Prof. Wickramasinghe is a pioneer of the new science of astrobiology, and is a prolific writer both of technical scientific papers as well as popular expositions of his ideas. Recent books include: Cosmic Genetic Evolution (Academic Press), Diseases from Outer Space, A Journey with Fred Hoyle, The Search for Our Cosmic Ancestry, Where did we come from? (World Scientific Publishing Singapore), and Our Cosmic Ancestry in the Stars (Inner Traditions USA). He was a Fellow of Jesus College, Cambridge from 1963-1973, Professor at University College Cardiff and Cardiff University from 1973-2011. Currently he is an Honorary Professor at the University of Buckingham UK, and also at the University of Ruhuna, Sri Lanka, the Sir John Kotelawala Defence University, Sri Lanka, and an Adjunct Professor at the National Institute of Fundamental Studies, Sri Lanka.