Lucky Planet: Why Earth Is Exceptional—and What That Means for Life in the Universe

Waltham, astrobiologist and geophysicist at the University of London, addresses the pressing question: How common is intelligent life in the universe? He examines the conditions necessary for life to begin and evolve into more complex forms, along the way exploring cosmological matters, such as star and planet formation, geological and meteorological concerns, as well as the nature of life itself. His basic, unsurprising premise is that vast amounts of time are required to produce intelligent life, but he goes further to explain that maintaining a relatively stable planetary climate for the bulk of that time is both essential and rare. “If this book has a theme, it is that climate is destiny.” Earth, as he shows, has a multiplicity of factors that have yielded a stable climate and, he argues, it is unlikely that a similar combination of conditions will appear very often. There are an enormous number of planets in the universe, but only a small percentage will have the requisite conditions. Waltham’s somewhat depressing conclusion is that “advanced civilizations elsewhere are inevitable, but they will also be so far away that we will never be able to communicate with them or even observe influences they may have on their galactic neighborhoods.” (Apr.)