J. Brit. Astron. Assoc., 107, 6, 1997, p. 304
Wiley/Praxis, 1997. ISBN 0-471-96605-3 (hbk), 0-471-96606-1 (pbk). Pp xx + 198, £45.00/£19.99.)
reviewed by John H. Rogers
The question of life on Mars engages a wide range of scientific disciplines. It embraces questions of how life originated and evolved on Earth; what the early Earth and Mars were like; what Mars is composed of today, below the surface that we see; how microfossils or chemical traces can be identified; and how robots or humans might search for fossils or present-day life on Mars. The recent excitement about evidence for life in the Martian meteorite ALH84001 has illustrated just how difficult these questions can be, and is presumably the reason for the appearance of this book in its second edition, which includes the meteorite evidence. The author considers all these fields of science, and also the more speculative fields in which he is an enthusiast, 'biophysical' systems theory and nanotechnology.
As this book is aimed at a general audience of scientists, undergraduates, and space enthusiasts, most readers will need basic explanation of at least some of these disciplines. However, this is not what the author sets out to provide. Rather, he offers an extended essay on the possibilities. This does pose problems for readers. On first glance, the book looks admirably comprehensive, with numerous pictures and diagrams of all the right things - chemical structures, the terrain of Mars and Europa, climatic cycles, spacecraft past and future, and much more. Unfortunately there is often no thorough explanation of what is actually shown in the diagrams and tables reproduced from other publications. The text is only loosely related to them, and does not give a solid explanation of most of the topics. Instead it rambles around many things, often incoherently with frequent non-sequiturs and changes of subject. Even crucial topics such as the Viking biology experiments or the theory of the 'RNA world' are just briefly mentioned and commented on. Indeed I wonder if the author understands many of the topics himself. In discussing the origin of life, why does he need to cite a Nobel prize winner from long ago to make the basic point that enzymes are much more efficient than inorganic chemistry (p.37)? Why does he not give a coherent account of ribozymes (catalytic RNA molecules which are hypothesised to have been crucial to the origin of self-replication in the 'RNA world' stage of evolution; p.36)? And how can he imagine that virus-like organisms could have originated in isolation on Earth or on Mars (pp.44, 71), as the fundamental property of a virus is that it must parasitise a more complex organism in order to replicate? Some ideas offered are even more whimsical, such as that life emerged from Earth's oceans onto land because of reduced gravity caused by a change in our position in the galaxy (p.20)!
The fields that were least familiar to this reviewer were the author's favourite ones of 'biophysics' and nanotechnology, so I waited for the author to convince me that they have real contributions to make. I never was convinced. His 'biophysics' seems to consist of abstract generalities about cycles and levels. The one example that is well established in the origin-of-life literature (Eigen's hypercycle model), characteristically, is mentioned but not explained, whereas the best conclusion the author can draw from this field of enquiry is that life involves cycles of replication of cells or organisms (p.45). Surely even laymen know this already. As for nanotechnology, there is a whole chapter with this title, but only 3 pages actually give an account of it, and these left the reviewer wondering how on Earth (let alone on Mars) the proposed miniature marvels could actually be achieved.
The final chapters discuss whether humans might sooner or later colonise and terraform Mars. But I do not think this book helps us very much along the road. It does not explain anything properly for someone who does not know that topic already, and does not have much that is original and important to say for anyone who does.
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