What do you think?
Rate this book
Life beyond Earth: The Search for Habitable Worlds in the Universe
What is life and where can it exist? What searches are being made to identify conditions for life on other worlds? If extraterrestrial inhabited worlds are found, how can we explore them? In this book, two leading astrophysicists provide an engaging account of where we stand in our quest for habitable environments, in the Solar System and beyond. Starting from basic concepts, the narrative builds scientifically, including more in-depth material as boxed additions to the main text. The authors recount fascinating recent discoveries from space missions and observations using ground-based telescopes, of possible life-related artefacts in Martian meteorites, extrasolar planets, and subsurface oceans on Europa, Titan and Enceladus. They also provide a forward look to future missions. This is an exciting, informative read for anyone interested in the search for habitable and inhabited planets, and an excellent primer for students in astrobiology, habitability, planetary science and astronomy.
296 pages, Hardcover
First published September 12, 2013
3 people are currently reading
55 people want to read
About the author
Athena Coustenis
6 booksDr. Athena Coustenis is an astrophysicist specializing in planetology. A French national, she is director of research, Centre national de la recherche scientifique, at LESIA, at the Paris Observatory, Meudon. She is involved in several space mission projects for the European Space Agency and for NASA.
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 5 of 5 reviews
December 3, 2013
When I was much younger, I read We Are Not Alone, by Walter Sullivan. In the forty or so years since then, the search for life outside our own planet has become far more sophisticated, and yet we’re still at the point where we haven’t found any. Are we searching correctly? Do we need to expand our ideas of how and what forms of life might develop on other worlds? Where should we look?
Dr. Athena Coustenis and Dr. Thérèse Encrenaz, both renowned astrophysicists, answer those questions in Life Beyond Earth: The Search for Habitable Worlds in the Universe. (Amazon link.)
One of the highest compliments I can pay to a science book like this is that I learned new things, and I have read many “is there life out there” tomes. It’s important here to state that, no, the authors are not proposing that there’s intelligent life (such as on Earth) on some of the other planets or moons of our solar system. But, given the right conditions, there might be, albeit very simple, life forms. It is certainly possible that organic or prebiotic molecules are in existence, especially anywhere there might be liquid water — which recent unmanned space missions indicate could exist below the surfaces of several of Jupiter’s and Saturn’s moons.
Life Beyond Earth carefully details how life can arise, where it can arise, and speculate on the likelihood of that happening. Dr. Athena Coustenis and Dr. Thérèse Encrenaz explore the possibilities of prebiotic, or life itself, existing under the (to us) unusual conditions on most of the planets and moons as well as outside the solar system.
This is a thorough and interesting survey of what we know and how we can learn more. Caution: This is written at, I want to say, a college level. If you are expecting the sort of easy, non-challenging read of a Carl Sagan book, you’ll be disappointed. A certain amount of chemistry and physics knowledge — not graduate, mind you, just that you remember your senior High School courses well — is recommended.
Lastly, Life Beyond Earth is profusely illustrated along with many color plates; I strongly urge you to purchase the physical hardcover rather than the Kindle edition for full enjoyment of them.
Dr. Athena Coustenis and Dr. Thérèse Encrenaz, both renowned astrophysicists, answer those questions in Life Beyond Earth: The Search for Habitable Worlds in the Universe. (Amazon link.)
One of the highest compliments I can pay to a science book like this is that I learned new things, and I have read many “is there life out there” tomes. It’s important here to state that, no, the authors are not proposing that there’s intelligent life (such as on Earth) on some of the other planets or moons of our solar system. But, given the right conditions, there might be, albeit very simple, life forms. It is certainly possible that organic or prebiotic molecules are in existence, especially anywhere there might be liquid water — which recent unmanned space missions indicate could exist below the surfaces of several of Jupiter’s and Saturn’s moons.
Life Beyond Earth carefully details how life can arise, where it can arise, and speculate on the likelihood of that happening. Dr. Athena Coustenis and Dr. Thérèse Encrenaz explore the possibilities of prebiotic, or life itself, existing under the (to us) unusual conditions on most of the planets and moons as well as outside the solar system.
This is a thorough and interesting survey of what we know and how we can learn more. Caution: This is written at, I want to say, a college level. If you are expecting the sort of easy, non-challenging read of a Carl Sagan book, you’ll be disappointed. A certain amount of chemistry and physics knowledge — not graduate, mind you, just that you remember your senior High School courses well — is recommended.
Lastly, Life Beyond Earth is profusely illustrated along with many color plates; I strongly urge you to purchase the physical hardcover rather than the Kindle edition for full enjoyment of them.
October 19, 2025
There’s a certain kind of silence that only space can give you — the silence of unimaginable distances, of light traveling for millennia before reaching your eyes. *Life Beyond Earth: The Search for Habitable Worlds in the Universe* is a book that listens closely to that silence and then dares to interpret it.
Written by **Jeffrey Bennett**, the same mind behind *Beyond UFOs* and the *Max Goes to Mars* series for younger readers, this book is both an introduction and a meditation on one of humanity’s most ancient questions: Are we alone? Bennett approaches it not like a preacher or a proselytizer but like a teacher with infinite patience and a spark of cosmic curiosity that’s downright contagious.
The first impression of the book is its humility. Bennett doesn’t posture as the man with answers; he’s the man with questions sharpened by data. He begins by setting the stage — not in deep space but on Earth itself, reminding readers that before we can find life beyond our planet, we must first understand what life really means here.
What are the conditions that make Earth habitable? What combination of chemistry, energy, and time makes a barren rock come alive? From this foundation, he builds outward, a kind of narrative telescope extending from microbial fossils to exoplanets, from early Earth to the edge of the observable universe.
His prose is that rare mixture of clarity and lyricism that makes science feel intimate. He describes the early search for life — from the Viking missions on Mars to the discovery of extremophiles in Earth’s harshest environments — not merely as a chronology of experiments but as an ongoing dialogue between humanity and the cosmos.
Each discovery, he suggests, revises our understanding of the possible. Life in boiling volcanic vents, under Antarctic ice, in acidic lakes, or within radioactive caves forces us to discard the arrogance of Earth’s centrality. If life thrives in such unthinkable conditions here, why not elsewhere?
The central premise Bennett develops is deceptively simple: life, as we know it, is not a miraculous exception but a natural consequence of cosmic laws. Wherever there is liquid water, energy flow, and the right chemistry, life should emerge.
But what he does so beautifully is make that idea feel personal. He invites readers to imagine not alien civilizations but alien ecosystems — planets with methane seas, moons with subsurface oceans, atmospheres tinted by biochemistry we can only guess at. The book’s wonder lies not in speculation about “little green men” but in the recognition that the universe is probably humming with microbial life, with evolutionary experiments in carbon and light.
Bennett’s discussion of exoplanets is particularly absorbing. Writing after the revolution brought by the Kepler Space Telescope, he revels in the statistics that suggest our galaxy alone may host billions of potentially habitable worlds. Yet he tempers that excitement with scientific caution. “Habitable,” he reminds us, doesn’t mean inhabited. The Goldilocks Zone — that narrow band where a planet can maintain liquid water — is a necessary condition but not a guarantee. Atmospheres, magnetospheres, stellar activity, and planetary composition all conspire to create a delicate balance. The miracle of Earth, Bennett implies, might not be that it supports life but that it has sustained it for billions of years.
What makes Bennett’s approach especially engaging is his insistence that the search for extraterrestrial life is not a fringe obsession but a profound scientific enterprise rooted in astronomy, biology, and chemistry. He guides the reader through the logic of the Drake Equation — that tantalizing formula that attempts to quantify the number of communicative civilizations in our galaxy — not as a rigid calculation but as a conceptual tool, a framework for curiosity. The Drake Equation becomes, in Bennett’s hands, less a numerical guess and more a philosophical koan: each variable a reflection of our assumptions about life, intelligence, and time.
Time, indeed, is one of the book’s subtlest themes. The universe is 13.8 billion years old; humanity’s scientific awareness of it, scarcely 500. The vast disparity invites both humility and wonder. Bennett meditates on the possibility that other civilizations might have risen and fallen long before Earth even cooled. Some might exist now, their signals en route through the void, destined to reach us centuries after their creators have vanished. Others might not yet exist, waiting for stars not yet born to give rise to life and thought. This temporal imagination — cosmic rather than human — is what gives *Life Beyond Earth* its philosophical gravitas.
He also excels at connecting scientific ideas with cultural and existential resonance. When discussing the Fermi Paradox — the great silence that contradicts the high probability of life — Bennett doesn’t resort to sensational theories of galactic empires or government cover-ups. Instead, he poses a quieter, more haunting question: what if intelligence, like a flare, burns brightly but briefly? What if civilizations, upon reaching a certain level of technological prowess, self-destruct before achieving interstellar communication? It’s a sobering reflection that turns the search for alien life into a mirror for our own species. The silence of the stars, in this light, becomes less an absence and more a warning.
One of the book’s most affecting sections deals with Mars — our planetary neighbor and eternal muse. Bennett recounts the history of Martian exploration with both scientific rigor and childlike enthusiasm. From Schiaparelli’s canals to the rovers’ dust-streaked selfies, Mars embodies humanity’s yearning to find kinship in the cosmos. He describes how discoveries like seasonal methane bursts and possible briny seeps have reignited the possibility of microbial life. Yet he also acknowledges the fragility of evidence, the ease with which hope can outrun data. Bennett’s Mars is not merely a destination for astronauts; it’s a test of scientific patience, a long-term dialogue between curiosity and caution.
The chapters on Europa and Enceladus — the icy moons of Jupiter and Saturn — shimmer with poetic fascination. Bennett describes their hidden oceans with reverence, evoking an image of alien seas warmed by tidal friction and chemical energy. Beneath those thick crusts of ice, he imagines hydrothermal vents teeming with microbial life — a mirror of Earth’s own deep-sea origins. His enthusiasm for the Europa Clipper and future missions to these moons is infectious; you can feel his conviction that the most profound discovery of our time might come not from distant exoplanets but from our own solar backyard.
What elevates *Life Beyond Earth* beyond other popular-science books on astrobiology is its moral and humanistic dimension. Bennett repeatedly emphasizes that the search for life elsewhere is not merely about discovery; it’s about perspective. To know that life exists beyond Earth would permanently alter our sense of identity and ethics. It would dethrone anthropocentrism and force us to reconsider what it means to be human in a universe of living worlds. Even if we never make contact, the act of searching itself is transformative — it cultivates humility, cooperation, and curiosity, virtues that our species urgently needs.
He weaves in the philosophical implications with deft subtlety. If life is common, then the universe is not indifferent but fecund; creation is not a singular miracle but a recurring theme. If life is rare — if we are the only conscious beings within reachable space — then our responsibility magnifies exponentially. We become the universe’s only voice, the single flicker of awareness amid cosmic darkness. Either way, the outcome is humbling. Bennett handles this duality beautifully, making the reader feel both infinitely small and immeasurably significant.
Stylistically, the book reads like a series of lucid meditations rather than a textbook. Bennett avoids jargon without sacrificing precision. His analogies are elegant: comparing stellar lifecycles to human lifetimes, planetary formation to artisanal craft, cosmic evolution to the growth of an organism. There’s a pedagogical grace to his writing — you can tell he’s a teacher who loves the subject, not just a scientist reporting data. Each chapter feels like a guided journey, and by the time you reach the end, you’ve not only learned but changed perspective.
A recurring motif is interconnectedness. Bennett insists that the search for extraterrestrial life is inseparable from understanding our own planet. Climate change, extinction, and ecological collapse, he argues, are not separate from cosmic inquiry but part of it. How can we hope to find life elsewhere if we cannot sustain it here? This ethical thread runs quietly but insistently through the narrative, giving the book a moral weight uncommon in science writing. Discovery, Bennett suggests, must be accompanied by stewardship.
When he turns to the possibility of intelligent life, the tone becomes contemplative rather than speculative. He considers what communication might look like between species separated by light-years — the limitations of electromagnetic signals, the possibility of non-technological intelligence, the role of art and mathematics as universal languages. He refuses to reduce the idea of alien intelligence to anthropomorphic expectations. Intelligence, he reminds us, might not look like us, think like us, or even value communication as we do. The humility embedded in that admission — that the universe might teem with minds utterly beyond our comprehension — is perhaps the book’s quietest but most profound revelation.
Throughout, Bennett balances hope with realism. He acknowledges that we might search for centuries without definitive proof of extraterrestrial life. But he argues that the search itself — the telescopes, the probes, the planetary missions — constitutes one of humanity’s greatest acts of faith. To look for life elsewhere is to affirm that the universe is knowable, that reason and curiosity can bridge the infinite. In this sense, *Life Beyond Earth* is less about aliens and more about the human spirit.
The book closes with a reflection that feels almost spiritual in its simplicity. Bennett suggests that the search for life beyond Earth is, at heart, an extension of the same impulse that drives art, music, and philosophy — the yearning to connect, to find meaning beyond the self. Whether or not we ever find extraterrestrial organisms, the very act of searching enlarges us. It reminds us that we are participants in a vast cosmic story still being written, that every question we ask becomes part of that narrative.
Reading *Life Beyond Earth* today, in an era when the James Webb Space Telescope sends back images of galaxies formed when the universe was still in its infancy, the book feels prophetic. Its optimism has aged well because it’s grounded in humility. Bennett doesn’t claim that discovery is imminent, only that it’s inevitable — if not by us, then by those who come after. He understands science as a relay race across generations, and his prose often gestures toward that continuity. Each mission, each experiment, each observation adds a verse to humanity’s evolving conversation with the cosmos.
What lingers after closing the book isn’t the promise of contact but the rekindled sense of wonder. Bennett’s universe is not hostile or indifferent; it’s participatory, inviting us to explore, to imagine, to question. His science writing becomes, in effect, a form of cosmic humanism — rational, empathetic, and suffused with awe.
For readers weary of sensational UFO claims or the dystopian fatalism that often infects space discourse, *Life Beyond Earth* offers something rare: clarity without cynicism, wonder without gullibility.
In the end, Bennett achieves what the best science communicators do — he makes the vast feel intimate. The search for habitable worlds, he suggests, is ultimately a search for ourselves: for proof that life is not an accident but a pattern, that the universe does not merely permit consciousness but perhaps celebrates it. Whether life elsewhere is discovered next year or next millennium, Bennett’s vision ensures that when it happens, we’ll recognize it not as a shock but as a homecoming.
Written by **Jeffrey Bennett**, the same mind behind *Beyond UFOs* and the *Max Goes to Mars* series for younger readers, this book is both an introduction and a meditation on one of humanity’s most ancient questions: Are we alone? Bennett approaches it not like a preacher or a proselytizer but like a teacher with infinite patience and a spark of cosmic curiosity that’s downright contagious.
The first impression of the book is its humility. Bennett doesn’t posture as the man with answers; he’s the man with questions sharpened by data. He begins by setting the stage — not in deep space but on Earth itself, reminding readers that before we can find life beyond our planet, we must first understand what life really means here.
What are the conditions that make Earth habitable? What combination of chemistry, energy, and time makes a barren rock come alive? From this foundation, he builds outward, a kind of narrative telescope extending from microbial fossils to exoplanets, from early Earth to the edge of the observable universe.
His prose is that rare mixture of clarity and lyricism that makes science feel intimate. He describes the early search for life — from the Viking missions on Mars to the discovery of extremophiles in Earth’s harshest environments — not merely as a chronology of experiments but as an ongoing dialogue between humanity and the cosmos.
Each discovery, he suggests, revises our understanding of the possible. Life in boiling volcanic vents, under Antarctic ice, in acidic lakes, or within radioactive caves forces us to discard the arrogance of Earth’s centrality. If life thrives in such unthinkable conditions here, why not elsewhere?
The central premise Bennett develops is deceptively simple: life, as we know it, is not a miraculous exception but a natural consequence of cosmic laws. Wherever there is liquid water, energy flow, and the right chemistry, life should emerge.
But what he does so beautifully is make that idea feel personal. He invites readers to imagine not alien civilizations but alien ecosystems — planets with methane seas, moons with subsurface oceans, atmospheres tinted by biochemistry we can only guess at. The book’s wonder lies not in speculation about “little green men” but in the recognition that the universe is probably humming with microbial life, with evolutionary experiments in carbon and light.
Bennett’s discussion of exoplanets is particularly absorbing. Writing after the revolution brought by the Kepler Space Telescope, he revels in the statistics that suggest our galaxy alone may host billions of potentially habitable worlds. Yet he tempers that excitement with scientific caution. “Habitable,” he reminds us, doesn’t mean inhabited. The Goldilocks Zone — that narrow band where a planet can maintain liquid water — is a necessary condition but not a guarantee. Atmospheres, magnetospheres, stellar activity, and planetary composition all conspire to create a delicate balance. The miracle of Earth, Bennett implies, might not be that it supports life but that it has sustained it for billions of years.
What makes Bennett’s approach especially engaging is his insistence that the search for extraterrestrial life is not a fringe obsession but a profound scientific enterprise rooted in astronomy, biology, and chemistry. He guides the reader through the logic of the Drake Equation — that tantalizing formula that attempts to quantify the number of communicative civilizations in our galaxy — not as a rigid calculation but as a conceptual tool, a framework for curiosity. The Drake Equation becomes, in Bennett’s hands, less a numerical guess and more a philosophical koan: each variable a reflection of our assumptions about life, intelligence, and time.
Time, indeed, is one of the book’s subtlest themes. The universe is 13.8 billion years old; humanity’s scientific awareness of it, scarcely 500. The vast disparity invites both humility and wonder. Bennett meditates on the possibility that other civilizations might have risen and fallen long before Earth even cooled. Some might exist now, their signals en route through the void, destined to reach us centuries after their creators have vanished. Others might not yet exist, waiting for stars not yet born to give rise to life and thought. This temporal imagination — cosmic rather than human — is what gives *Life Beyond Earth* its philosophical gravitas.
He also excels at connecting scientific ideas with cultural and existential resonance. When discussing the Fermi Paradox — the great silence that contradicts the high probability of life — Bennett doesn’t resort to sensational theories of galactic empires or government cover-ups. Instead, he poses a quieter, more haunting question: what if intelligence, like a flare, burns brightly but briefly? What if civilizations, upon reaching a certain level of technological prowess, self-destruct before achieving interstellar communication? It’s a sobering reflection that turns the search for alien life into a mirror for our own species. The silence of the stars, in this light, becomes less an absence and more a warning.
One of the book’s most affecting sections deals with Mars — our planetary neighbor and eternal muse. Bennett recounts the history of Martian exploration with both scientific rigor and childlike enthusiasm. From Schiaparelli’s canals to the rovers’ dust-streaked selfies, Mars embodies humanity’s yearning to find kinship in the cosmos. He describes how discoveries like seasonal methane bursts and possible briny seeps have reignited the possibility of microbial life. Yet he also acknowledges the fragility of evidence, the ease with which hope can outrun data. Bennett’s Mars is not merely a destination for astronauts; it’s a test of scientific patience, a long-term dialogue between curiosity and caution.
The chapters on Europa and Enceladus — the icy moons of Jupiter and Saturn — shimmer with poetic fascination. Bennett describes their hidden oceans with reverence, evoking an image of alien seas warmed by tidal friction and chemical energy. Beneath those thick crusts of ice, he imagines hydrothermal vents teeming with microbial life — a mirror of Earth’s own deep-sea origins. His enthusiasm for the Europa Clipper and future missions to these moons is infectious; you can feel his conviction that the most profound discovery of our time might come not from distant exoplanets but from our own solar backyard.
What elevates *Life Beyond Earth* beyond other popular-science books on astrobiology is its moral and humanistic dimension. Bennett repeatedly emphasizes that the search for life elsewhere is not merely about discovery; it’s about perspective. To know that life exists beyond Earth would permanently alter our sense of identity and ethics. It would dethrone anthropocentrism and force us to reconsider what it means to be human in a universe of living worlds. Even if we never make contact, the act of searching itself is transformative — it cultivates humility, cooperation, and curiosity, virtues that our species urgently needs.
He weaves in the philosophical implications with deft subtlety. If life is common, then the universe is not indifferent but fecund; creation is not a singular miracle but a recurring theme. If life is rare — if we are the only conscious beings within reachable space — then our responsibility magnifies exponentially. We become the universe’s only voice, the single flicker of awareness amid cosmic darkness. Either way, the outcome is humbling. Bennett handles this duality beautifully, making the reader feel both infinitely small and immeasurably significant.
Stylistically, the book reads like a series of lucid meditations rather than a textbook. Bennett avoids jargon without sacrificing precision. His analogies are elegant: comparing stellar lifecycles to human lifetimes, planetary formation to artisanal craft, cosmic evolution to the growth of an organism. There’s a pedagogical grace to his writing — you can tell he’s a teacher who loves the subject, not just a scientist reporting data. Each chapter feels like a guided journey, and by the time you reach the end, you’ve not only learned but changed perspective.
A recurring motif is interconnectedness. Bennett insists that the search for extraterrestrial life is inseparable from understanding our own planet. Climate change, extinction, and ecological collapse, he argues, are not separate from cosmic inquiry but part of it. How can we hope to find life elsewhere if we cannot sustain it here? This ethical thread runs quietly but insistently through the narrative, giving the book a moral weight uncommon in science writing. Discovery, Bennett suggests, must be accompanied by stewardship.
When he turns to the possibility of intelligent life, the tone becomes contemplative rather than speculative. He considers what communication might look like between species separated by light-years — the limitations of electromagnetic signals, the possibility of non-technological intelligence, the role of art and mathematics as universal languages. He refuses to reduce the idea of alien intelligence to anthropomorphic expectations. Intelligence, he reminds us, might not look like us, think like us, or even value communication as we do. The humility embedded in that admission — that the universe might teem with minds utterly beyond our comprehension — is perhaps the book’s quietest but most profound revelation.
Throughout, Bennett balances hope with realism. He acknowledges that we might search for centuries without definitive proof of extraterrestrial life. But he argues that the search itself — the telescopes, the probes, the planetary missions — constitutes one of humanity’s greatest acts of faith. To look for life elsewhere is to affirm that the universe is knowable, that reason and curiosity can bridge the infinite. In this sense, *Life Beyond Earth* is less about aliens and more about the human spirit.
The book closes with a reflection that feels almost spiritual in its simplicity. Bennett suggests that the search for life beyond Earth is, at heart, an extension of the same impulse that drives art, music, and philosophy — the yearning to connect, to find meaning beyond the self. Whether or not we ever find extraterrestrial organisms, the very act of searching enlarges us. It reminds us that we are participants in a vast cosmic story still being written, that every question we ask becomes part of that narrative.
Reading *Life Beyond Earth* today, in an era when the James Webb Space Telescope sends back images of galaxies formed when the universe was still in its infancy, the book feels prophetic. Its optimism has aged well because it’s grounded in humility. Bennett doesn’t claim that discovery is imminent, only that it’s inevitable — if not by us, then by those who come after. He understands science as a relay race across generations, and his prose often gestures toward that continuity. Each mission, each experiment, each observation adds a verse to humanity’s evolving conversation with the cosmos.
What lingers after closing the book isn’t the promise of contact but the rekindled sense of wonder. Bennett’s universe is not hostile or indifferent; it’s participatory, inviting us to explore, to imagine, to question. His science writing becomes, in effect, a form of cosmic humanism — rational, empathetic, and suffused with awe.
For readers weary of sensational UFO claims or the dystopian fatalism that often infects space discourse, *Life Beyond Earth* offers something rare: clarity without cynicism, wonder without gullibility.
In the end, Bennett achieves what the best science communicators do — he makes the vast feel intimate. The search for habitable worlds, he suggests, is ultimately a search for ourselves: for proof that life is not an accident but a pattern, that the universe does not merely permit consciousness but perhaps celebrates it. Whether life elsewhere is discovered next year or next millennium, Bennett’s vision ensures that when it happens, we’ll recognize it not as a shock but as a homecoming.
April 8, 2018
This is neither an especially technical book nor one written for a popular audience -- it's somewhere in between. To me, that fills a gap. Rather than simple presentations and descriptions of key concepts, Coustenis and Encrenaz go into some depth, explaining some of the more complex aspects that really make these concepts, and their applications, interesting.
For example, a star's habitable zone is usually presented in popular treatments as a matter of a planet's orbital distance relative to its star's energy output. But it's more than that -- what makes a planet potentially habitable has more to do with all of the energy sources available to its surface, subsurface, and even atmospheric environments and the chemistry those energy sources can support. This is what makes our own system's Europa, Titan, and Enceladus candidates for life, while they actually sit well outside a simply calculated habitable zone.
Similarly, Coustenis and Encrenaz go into some detail on other topics, such as how exoplanets are detected, the chemistry of life, potentials for alternative life chemistries, planet compositions, and orbital migration. The authors are scientists, not science writers, and it shows, although I think they write clearly and with a fair understanding of what is going to be understandable to a non-specialist audience.
The bulk of the book is about our solar system. Four of its six chapters take up the fundamentals of life, planet formation, and the potential for life on solar system planets and moons. Even Mercury, Neptune, and trans-Neptunian objects are included in short discussions, along with more extensive discussions of Mars and the moons of Jupiter and Saturn. The advantage of focusing on solar system objects is that we know so much more about them than we do about exoplanets. We have sent probes to all of them, we know something of their atmospheres, surfaces, and subsurfaces, and, in some cases, we have followed the evidence to some tantalizing possibilities for life. Concentrating on them turns abstract speculation into grounded, concrete investigations.
The final two chapters take up exoplanets and more speculative topics on space exploration, potentials for human habitats beyond earth, and contact with alien life. These topics are treated much more briefly than you'll find in other books dedicated to exoplanets and possible extraterrestrial civilizations.
The tone of the book is factual, not argumentative. There's no real debate here about the likelihood of life beyond earth, although the debate is mentioned. Naturally, I think, the authors are optimistic about life beyond earth. There is after all a selection bias at work in this field-- scientists are unlikely to devote their careers to a field they don't think is promising.
All in all, I came away with a much better understanding of the central questions. I'd recommend it to anyone with a depth of interest in the field and a desire to wade out into some of the complexities.
For example, a star's habitable zone is usually presented in popular treatments as a matter of a planet's orbital distance relative to its star's energy output. But it's more than that -- what makes a planet potentially habitable has more to do with all of the energy sources available to its surface, subsurface, and even atmospheric environments and the chemistry those energy sources can support. This is what makes our own system's Europa, Titan, and Enceladus candidates for life, while they actually sit well outside a simply calculated habitable zone.
Similarly, Coustenis and Encrenaz go into some detail on other topics, such as how exoplanets are detected, the chemistry of life, potentials for alternative life chemistries, planet compositions, and orbital migration. The authors are scientists, not science writers, and it shows, although I think they write clearly and with a fair understanding of what is going to be understandable to a non-specialist audience.
The bulk of the book is about our solar system. Four of its six chapters take up the fundamentals of life, planet formation, and the potential for life on solar system planets and moons. Even Mercury, Neptune, and trans-Neptunian objects are included in short discussions, along with more extensive discussions of Mars and the moons of Jupiter and Saturn. The advantage of focusing on solar system objects is that we know so much more about them than we do about exoplanets. We have sent probes to all of them, we know something of their atmospheres, surfaces, and subsurfaces, and, in some cases, we have followed the evidence to some tantalizing possibilities for life. Concentrating on them turns abstract speculation into grounded, concrete investigations.
The final two chapters take up exoplanets and more speculative topics on space exploration, potentials for human habitats beyond earth, and contact with alien life. These topics are treated much more briefly than you'll find in other books dedicated to exoplanets and possible extraterrestrial civilizations.
The tone of the book is factual, not argumentative. There's no real debate here about the likelihood of life beyond earth, although the debate is mentioned. Naturally, I think, the authors are optimistic about life beyond earth. There is after all a selection bias at work in this field-- scientists are unlikely to devote their careers to a field they don't think is promising.
All in all, I came away with a much better understanding of the central questions. I'd recommend it to anyone with a depth of interest in the field and a desire to wade out into some of the complexities.
March 13, 2022
Exellent
Well written and easy to follow for a novice on this topic. I really enjoyed the chapter what we do once we find life beyond earth.
Well written and easy to follow for a novice on this topic. I really enjoyed the chapter what we do once we find life beyond earth.
July 3, 2024
I did not get very far into this book. Despite the author's stated intention in the introduction that this book was intended for "lay" readers as well as students... it isn't. I have an undergraduate and a graduate degree, with a wide sci-fi reading history and one college-level astronomy class. Even a few pages into the first chapter, I could see I would have to take notes if I was going to continue. The writing was pretty academic, not really approachable for the average member of the public. That style is fine, but know your intended audience. Not for me.
approved for the eARC from NetGalley but didn't get to it in time; sampled thanks to my local public library.
approved for the eARC from NetGalley but didn't get to it in time; sampled thanks to my local public library.
Displaying 1 - 5 of 5 reviews