This volume contains papers presented at an international conference to celebrate Fred Hoyle's monumental contributions to astronomy, astrophysics and astrobiology and more generally to humanity and culture. The contributed articles highlight the important aspects of his scientific life and show how much of an example and inspiration he has been for over three generations in the 20th century. There are a few people of whom it could be said they changed the way we perceive the world. Galileo Galilei, Nicholas Copernicus and Isaac Newton were amongst these. The inclusion of Fred Hoyle in this elite group may be contentious at the moment for the reason that in challenging the most cherished of Holy Grails in science he unwittingly offended many. But once the dust has settled over the many disputes that were raised and in the fullness of time there can be little doubt that Fred Hoyle will be ranked alongside these figures of history. Hoyle perceived science with an indomitable passion and an obsessive desire to find the truth wherever it lay. His singleness of purpose in this great mission and his deep suspicion of orthodoxy, his powerful intellect and imagination set him apart from most of his contemporaries in the last century. This volume includes papers presented at a commemorative conference held in Cardiff in June 2002. The material divides naturally into several sections: Personal Reminiscences, Stellar Structure and Evolution, Cosmology, Interstellar Matter, Comets and finally Panspermia. Each article pays its own tribute to Fred Hoyle for his inspiration and guidance that led to major breakthroughs in astrophysics and space science throughout the 20th century.