Book reviews: On habitable environments, and the rovers that explore them

I have accumulated a huge pile of books to review and regret that I didn’t get to it earlier. In recognition of the fact that I’m never going to finish reading all of these books, I’ve sorted through the pile of the ones I've started, and picked out books that I can definitely recommend as being worthwhile to explore. Oddly (for me), nearly all of them fit a single theme: life in the universe -- what it might be, and where it might be found. Habitable environments on Earth and elsewhere in the solar system came up in a lot of books I received this year, including the one I reviewed earlier, Alien Seas. Here are some more titles I've found to be worth a place in my library.

Frontiers of Astrobiology, edited by Chris Impey, Jonathan Lunine, and Jose Funes, is an academic text reviewing the state of the science. Astrobiology is an unusual science in that we actually have no data on life elsewhere in the solar system. So the first chapters take pains to explain what exactly astrobiology is – and stepping back even further, how to define “life” in a way that is useful to our search for it elsewhere. Then it goes on to several chapters on the history of life on Earth (with contributions by authors like Roger Summons and James Kasting, whose names I recognize from background reading on Curiosity’s mission to search for habitable environments). The next part of the book explores habitable environments across the rest of the solar system (with chapters by people like Athena Coustenis, Julie Castillo-Rogez, and Lunine), and the final one examines the possibility of life elsewhere in the universe (including contributions from Jill Tarter and Sara Seager). In fact, the structure of this book is strikingly parallel to that of Alien Seas – it’s just at a more rigorously academic level. Each chapter is relatively short and has a lengthy bibliography, so I plan to keep this book on my shelf as a useful resource providing a concise, well-referenced introduction to each aspect of astrobiology, with useful guidance to where I can read more.

Earth: Evolution of a Habitable World is a really unusual textbook – I’ve never seen anything quite like it. You know how many discussions of the significance of some new scientific discovery are usually wrapped up with an arm-waving statement about how the discovery will inform our understanding of Earth? Well, this is the book that takes all that we've learned about other planets in and out of our solar system and explains what it's taught us about Earth. So it’s an Earth science textbook, but it approaches Earth from a planetary perspective. Actually, it approaches Earth from even farther away than that; the first four chapters deal with the cosmic and slowly zoom in on our little corner of the cosmos. It treats Earth as we tend to treat the other planets in planetary science texts. One unusual result of that treatment is that this is the first Earth science textbook I’ve come across that gives anything like proportional weight to all the different ages of Earth’s history, from the solar system’s formation through Hadean, Archean (on which there are four chapters), and then finally the Phanerozoic (two chapters) before indulging itself in four chapters on modern Earth. Throughout, it examines how the environmental changes on Earth affected the chemistry of life. Three of these final four chapters concern Earth’s climate. This would be a spectacular text for a course providing a perspective on Earth and planetary science and modern issues in our stewardship of the Earth for students majoring in fields outside the geosciences. Prospective lawyers and doctors, teachers, mathematicians, and physicists would all benefit from this class. It could even give geology students perspective on the "deep time" that is beyond the vast majority of Earth's geologic record, and on Earth's place in the solar system. The author, Jonathan Lunine, is a scientist who knows his planetary climates, having studied atmospheres of worlds inside and outside our solar system, and who has done lots of recent work on astrobiology (such as the previous book in this list).

This next book may seem an odd one in the list because it’s clearly a biology book, not a space science one. But Ross Piper's Animal Earth has been a wonderful, eye-opening book to read, and not just because of its glorious color photos. It explores the full breadth of animal life on Earth, devoting chapters to each of 35 "lineages" on the family tree of kingdom Animalia. Only one of those lineages contains vertebrates. Yes, this enormous, beautiful, 320-page book devotes only 14 pages to Craniata. Most of the rest are varieties of life forms I’ve hardly heard of, from Acoelomorpha to Xenoturbidella, astonishing in the diverse ways that they approach the problems that face all living things: eating, excreting, and reproducing. Reading this book has made me appreciate how important it is that scientists recognize the diversity of expressions of life on Earth before we can begin to look for it elsewhere in the universe. This book can be appreciated for its pictures alone, but it's a good read, too. The text starts out a bit on the dry side, even a bit stuffy. But as I’ve continued reading the book it seems that the author’s enthusiasm for his subject has become unbound, until, by the chapter on that largest of animal groups, the arthropods, he can hardly contain his amazement and wonder at the creativity and variety of creeping, crawling, squirming, flapping, soaring, burrowing, floating, parasitizing life on Earth.

Boy, do I wish I had had a copy of Gordon Osinski and Betty Pierazzo’s Impact Cratering when I took Pete Schultz’s impact cratering class in grad school. Impact cratering is an incredibly important geologic process to understand when you’re studying the solid surfaces of planets and moons, but there was no synthesis available when I was a student, at least not one written from a geology perspective. This book contains exactly what you’d wish a text for a graduate-level class in impact cratering to do, and it’s really well-illustrated. Example chapters include ones on: the population of impactors (by Patrick Michel and Allesandro Morbidelli); the physics of the impact process (Jay Melosh); the kinds of alteration experienced by rocks that suffer impacts, like shock metamorphism, impact melting, and so on. The book also includes several case studies of specific Earth impact craters from both remote sensing and geological survey perspectives. But there are a few chapters that I think would be important reading outside the context of an impact cratering class, including ones on the environmental effects of impacts (by Pierazzo and Melosh), impact-induced hydrothermal activity (Kalle Kirsimäe and Osinski), and the geomicrobiology of impact structures (Charles Cockell, Osinski, and Mary Voytek). With all the talk these days about possible habitable environments either created by an impact crater or found in hydrothermal systems associated with impact craters, I think these chapters provide important references for how such environments really behaved.

Finally, the only book on this list that doesn't squeeze in to the life-in-the-universe theme. Haynes Publishing is best known for its illustrated owners’ manuals and do-it-yourself instructional texts. While there’s no do-it-yourself aspect to Mars exploration (yet!), the NASA Mars Rovers Owners’ Workshop Manual provides the same level of technical detail on the design and operation of Sojourner, Spirit, Opportunity, and Curiosity, with a sprinkling of information about the other Mars landers and orbiters for good measure. The text is absolutely packed with technical details and precise numerical specifications, details I’ve already found useful in writing my book. For example: you can learn that the track of Curiosity’s center wheels is located 8.3 centimeters outside the track of the front and rear wheels; or every geometric description of each camera that you could possibly want, or every center wavelength of every Mastcam filter. These are all contained within the text, which can sometimes make it a morass of numbers, but the book is lavishly and appropriately illustrated in color, making it easy for me to seek and find the information I’m interested in. It appears they held the book’s publication until just after the landing, so the Curiosity section relies mostly upon material that existed prior to landing, but does include the very first images and science results from the surface of Mars. The text makes frequent comparisons between missions, providing context for understanding the evolution in capability from one rover to its successor.