| LIFE AS WE DO NOT KNOW IT The NASA Search for (and Synthesis of) Alien Life Peter D. Ward New York: Viking, 2006 |
Rating: 4.5 High |
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| ISBN 0-670-03458-4 | 292p. | HC/BWI | $25.95 | |
Science faces many mysteries. One of the deepest and most daunting is: How did the first life arise from non-living substances? We know that this transition happened, on Earth at least, for the Cosmos began as lifeless matter and Earth is now raucous and vibrant with life. But when it happened, how long it took, what conditions were required, and what laws of physics and chemistry apply are world-class conundrums.
Peter Ward informs us here that there is a host of scientists probing the myriad facets of those conundrums. This quest is inspired by the notion that, given the right conditions, elementary life forms arise due to the operation of chemical laws. The details of those laws are only partly understood, so the various concepts of life's origin do not rank as scientific theories. Yet much has been discovered. For example, it is known which chemical elements must be present (at least for life as we know it) and what sources of energy are suitable. It was recently learned that clay minerals can act as scaffolds for the formation of complex organic chemicals, while water (as in the warm little pond favored by Darwin) would probably not do the trick since it tends to break up (deaminate) RNA and DNA.
Practitioners of the nascent science of astrobiology — the study of life beyond Earth — know that there are two ways to proceed in that study: to discover unearthly life in situ; or to create it in the laboratory. The creation of life by humankind, once thought merely a fantastical notion to be relegated to bad movies or the pages of Mary Shelley's novel Frankenstein, is fast becoming a real scientific possibility. But of course no scientist truly believed artificial life could never be created in the laboratory. It is, after all, the logical end of the path we're following through synthesis of amino acids to the unraveling of the genetic code and on to the still more complex puzzle of how proteins are formed by the expression of portions of that code.
The search for alien life outside our blue-marble planet Earth has been under way for some fifty years, without results. None of the antennas scanning the skies has found a signal from ET. None of the robotic probes landed on another planet has found so much as a microbe, nor even a fossil or other trace1 of one. These searches will continue, but as astrobiology comes into its own as a multidisciplinary science — a process in which Peter Ward plays a part — earthbound experiments are growing in importance. Ward describes how these experiments are winkling out new bits of knowledge about conditions under which life can form and thrive.
Field work is important too, for much remains to be learned from the fossil record as well as from living species. Hidden havens on our homeworld still harbor unknown forms: not only the hardy microbes of Antarctic lakes or the alien-seeming biota clustering around sub-ocean volcanic vents, but large surface animals and plants. (Just last year there were several such discoveries: conifers in northwest Viet Nam, a kangaroo, birds and 20 new species of frogs in the Foja Mountains of New Guinea.) There may even, Ward suggests, be life forms that are truly alien2 lurking right under our noses. He raises a vexing question: Will we recognize alien life even if we find it?
The book's 14 chapters cover the latest research in astrobiology, and the range of possibilities currently imagined for alien life, fairly thoroughly (if not always with appropriate depth and consistency.) Along the way you'll read about exciting developments like the Chen-Rasmussen Protocell3 (page 126). Ward writes in a choppy, likable style that reminded me of the way George H. W. Bush used to speak on television. The text is filled with information, sprinkled with speculation, and spiced up by pop-culture references. There is a good index, and Ward provides a list of references for each chapter.
Yet while I enjoyed the exposition of cutting-edge science, the chapters I liked best were those into which Ward introduced some history and politics: Chapters 9 & 10.
I knocked the book's rating down one notch because of occasional continuity errors. For example, after having devoted multiple pages to the Huygens probe, Ward should not say that no human-made object has ever reached Titan (Huygens did.) There are others, as noted in the Errata list. Nevertheless, it conveys a lot of information about this fast-changing field (which no doubt keeps Ward very busy as well)4 and I recommend it.
To contact Chris Winter, send email to this address.