The search for life in the Universe, once the domain of science fiction, is now a robust research program with a well-defined roadmap, from studying the extremes of life on Earth to exploring the possible niches for life in the Solar System and discovering thousands of planets far beyond it. In addition to constituting a major scientific endeavor, astrobiology is one of the most popular topics in astronomy, and is of growing interest to a broad community of thinkers from across the academic spectrum. In this volume, distinguished philosophers, theologians, anthropologists, historians and scientists discuss the big questions about how the discovery of extraterrestrial life, whether intelligent or microbial, would impact society. Their remarkable and often surprising findings challenge our foundational concepts of what the discovery of alien life may hold for humankind. Written in easily accessible language, this thought-provoking collection engages a wide audience of readers from all backgrounds. "Are we alone in the cosmos? If yes, we can never be sure. If no, we might well have an answer within the decade. The 22 authors of these fascinating and informative essays say no, we are not alone, despite the fact that so far not a shred of evidence has been found for the existence of life elsewhere in the universe. But just in case they are right, we need to start thinking about the possibility that we are not alone, and here is a good place to start." Owen Gingerich, Harvard-Smithsonian Center for Astrophysics and author of God's Planet "… this is a very worthwhile text, presenting a number of fascinating, novel possibilities on how the days after "first contact" might look." John Rowlands, Astronomy Now 'In [this book] Steven J. Dick tries to answer this question compiling a series of essays from a carefully selected group of experts. These essays deal with a wealth of questions. From the most obvious… To the most far-fetched … The essays are very well written and engaging. Even more impressive, despite being a collection of essays, this book is quite cohesive with a clear and unitary flow. This is greatly helped by the introductions written by Steven J. Dick for the whole book as well as for each of its parts. Overall, this is a very interesting and entertaining book. It’s a pleasant read for anyone wanting to know more about the current search for extraterrestrial life - and wanting to get ready for a potential detection.' Giovanni Volpe, Contemporary Physics This book discusses the big questions about how the discovery of extraterrestrial life, whether intelligent or microbial, would impact society and humankind. Steven J. Dick held the 2014 Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology at the John W. Kluge Center of the Library of Congress. In 2013 he testified before Congress on the subject of astrobiology. He served as the Charles A. Lindbergh Chair in Aerospace History at the National Air and Space Museum (2011–2012), and as the NASA Chief Historian and Director of the NASA History Office (2003–2009). He is the recipient of numerous awards, including the NASA Exceptional Service Medal and the Navy Meritorious Civilian Service Medal, and is author or editor of twenty books, including The Biological Universe (1996). He was awarded the 2006 LeRoy E. Doggett Prize for Historical Astronomy of the American Astronomical Society. In 2009, the International Astronomical Union designated minor planet 6544 stevendick in his honor.