A provocative, anecdotal book about the possibility of extra–terrestrial life by a leading young astronomer and advisor to NASA.

It's been a quarter of a century since Carl Sagan first addressed the general public from the perspective of a practicing scientist confronting the possibility of extraterrestrial life. We've learned a lot in those 25 years, and leading astronomer David Grinspoon is well prepared to carry Sagan's legacy forward to a new generation of readers. In Lonely Planets, Grinspoon explores the big questions with unusual authority, passion and panache: How widespread are life and intelligence in the cosmos? Is life on Earth an accident or in some sense the 'purpose' of this universe? And how can we, working from a sample size of one, even begin to think intelligently about life on distant planets? He gives us new ways of thinking about life and outlines his controversial view that Venus, not Mars, is the best candidate for finding nearby life. Lonely Planets concludes with provocative speculations on human destiny and reveals how the search for ET life unites our spiritual and scientific quests for connection with the cosmos.

Examining scientific data, reviewing historical records and sympathetically analyzing folk beliefs, Grinspoon presents a comprehensive history of ideas about extraterrestrial life and offers provocative new scientific speculations. Rich in personal, often amusing anecdotes, his narrative expertly guides readers through history, science, and prevailing beliefs about life on other planets.