". . . a must-have for anyone interested in biology, evolution, or the new and startling discoveries we may expect to find in the coming decades . . ."
- Astronomy (April 2002, p.87)

". . . an enthralling introduction to the new science of astrobiology and the old, still exhilarating philosophical question of our place in the universe."
- Lynn Margulis, author of Symbiotic Planet

"A lucid and surprisingly accurate introduction to the field of astrobiology and a thoughtful response to the Rare Earth hypothesis. Carl Sagan would have been pleased to see this."
- James R. Kasting, Penn State Astrobiology Research Center