This book explains how life came about on Earth and what that might mean for life elsewhere in the universe. It may seem odd that life’s origins on Earth is relevant to this otherwise extraterrestrial sub-discipline, but that bit of biology offers insight into what is necessary for life—at least life as we know it. There is also the question of whether life originated entirely within Earth’s primordial soup, or whether there was an extraterrestrial ingredient necessary.” [Note: we aren’t talking about an advanced civilization placing creatures here so much as raw materials frozen in space dust or a meteorite. This is the idea of panspermia that once had a substantial following.]
If you’re interested in whether there might be life beyond our planet, this little introduction will give you the basic insights into where it might be found and what it might be like. Though the book deals with a highly technical subject, it’s written with the non-expert in mind.
The book consists of eight chapters. The first chapter defines the subject of “astrobiology,” which is important as it’s not exactly a household term—and is arguably an ill-chosen term to boot. However, chapter one also defines life and outlines what are the necessities for the development of life. The second chapter explores what type of celestial body life might reside upon–or in. We tend to think narrowly of other planets like ours, but what about moons or meteorites, or even space dust? More broadly, this chapter gives the reader a primer on cosmology and astronomy as is relevant to the development of life. Chapter three evaluates the conditions which proved conducive to spawning life on Earth. This is followed by a chapter that looks at how the Earth provided an environment in which life could flourish, even allowing for the evolution of intelligent lifeforms. Chapter five explains how genes and the chemistry of life contribute to the perpetuation of life.
Chapters six and seven both answer the question of where we might expect to find extraterrestrial life. The former discusses promising locales for life within our solar system and the latter is about the space beyond. Needless to say, chapter six is a great deal more specific; it actually proposes nine celestial bodies in the solar system that could theoretically harbor life, and expounds upon which are most and least promising and why. Chapter seven is more about what kinds of places we might expect to find life, and where we might direct our investigations. While scientists are finding new planets all the time, it is a relatively new capability and these distant bodies are only discovered through indirect evidence. The last chapter is a brief one that discusses “controversies and prospects.” With respect to controversies the primary contender is the Rare Earth hypothesis that suggests that life may not be so common as we expect by virtue of the massive number of solar systems out there. As for prospects, that is just a couple of pages on the most likely contenders at the time the book was written.
The book has about a dozen illustrations, mostly explanatory diagrams and all in black-and-white. It also has a two-page further reading section. However, that’s it as far as ancillary matter is concerned.
I found this book to be interesting and a good way to get up to speed on the basic concepts necessary to understand the search for extraterrestrial life. I’d recommend it for others who’d like to do the same.