How do we fit into the Universe? Are we alone? By taking these questions seriously, astrobiology is attracting public attention and students. Two new astrobiology journals have sprung up and NASA funding is flowing again. With the publication of Planets and Life, a textbook for graduate students and upper level undergraduates, astrobiology is taking another large step towards formalizing itself as an established multidisciplinary field. If you're becoming an astrobiologist, this thick authoritative text contains the stuff you need to know. Job-conscious Ph.D. students studying astrobiology and worried about some of its flakier adherents can now sleep easier.

It's not easy to unify a multidisciplinary field whose main focus (extraterrestrial life) may not exist, but this new astrobiology textbook pulls it off. Planets and Life is a well-organized compilation of 28 chapters by 50 contributing authors. Coming from such a disparate group of authors, the quality of the writing is surprisingly uniform and high. The subjects span the astrobiological gamut: formation of Earth-like habitable planets, planetary atmospheres, the earliest records of life on Earth, evolution of metabolism, extremophiles in hydrothermal vents and in ice, possible biochemistries of alien life, and the search for extraterrestrial intelligence. With so many authors and so many topics, the book could have suffered the fate of being a mixed miscellaneous collage, like so many proceedings volumes, but it doesn't. No two authors, or even a small committee of experts, could have presented so many topics at such a high level. The editors, Woodruff Sullivan and John Baross, are at the University of Washington, which has taken the lead in providing a Certificate in Astrobiology at the graduate level (see http://depts.washington.edu/astrobio/).

So much information is crammed into this 604-page text that the margins are almost too small to write in – and no glossy colour images are included to attract bored undergraduates. The numerous references at the end of each chapter are up-to-date (~mid 2007) and particularly welcome in this new multidisciplinary field where most of us are struggling to integrate information from half a dozen disciplines. I'll use Planets and Life to make sure some of my half-baked research ideas die honorably in private, or come to life confidently with the knowledge of what has and what has not already been done. If the Australian National University (where I work) ever sets up a course in astrobiology, I'd recommend Jonathan Lunine's Astrobiology: A Multidisciplinary Approach for undergraduates and Planets and Life for graduate students. Even if extraterrestrials don't exist . . . even if we are alone . . . the combination of details and big picture thinking embodied in this new text will go far to describe our current understanding of how we came to be and how we fit into the universe.