Is there any life out there?

Astrobiology. A brief introduction

Kevin Plaxco and Michael Gross 

Baltimore, US: Johns Hopkins University Press | 2006 | 272pp | ?16.50 (SB) | ISBN 0801883679 

Reviewed by Anthony Campbell

Where did life begin? Is there life out there? These questions have intrigued scientist and non-scientist alike for centuries. In this timely book, Kevin Plaxco and Michael Gross analyse the key issues that must be addressed if we are to answer these questions. The science of astrobiology is new, but many universities are now developing research and teaching programmes on the origins of life, and how we might prove that life exists elsewhere in the universe.  

This book is comprehensive and readable, involving physics, chemistry and biology, including key biochemical processes in life. It was pleasing to find discussions on the main puzzles about the origin of live, including what I regard as the three greatest mysteries of all - how life crossed the Rubicon to choose left handed amino acids in proteins, right handed sugars in DNA, and ATP as its energy currency. These show what analyses are needed if we are to search for life out there.  

The idea that life is cosmic, and that microbes are raining down on us continuously, has been propagated in many scientific papers and books by Sir Fred Hoyle and Chandra Wickramasinghe. I was disappointed therefore that their pioneering work on panspermia was not discussed in any depth. Plaxco and Gross also have not explained the secret to understanding the energetics of life. There are many textbooks that still perpetuate the myth of the ATP ’energy-rich’ bond. Astrobiology  tells us that ’life requires an external disequilibrium’, yet fails to nail the flawed concept of the energy-rich bond into its rightful coffin. Nevertheless, Astrobiology  will be a good read for all those who are fascinated by the search for extraterrestrial life, and the origin of life on our own planet. I shall certainly value it in my own library.