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À l'aube de nouveaux horizons
Qui de mieux que Nathalie A. Cabrol pour faire le point dans un essai vivant et didactique sur l’une des questions les plus profondes de l’humanité : sommes-nous seuls dans l’Univers ? La directrice scientifique du centre SETI (Search for Extraterrestrial Intelligence, « Recherche d’intelligence extraterrestre ») aborde tour à tour l’exploration de notre système solaire, la recherche des exoplanètes, celle des signaux extraterrestres et les types de civilisations ou vies qu’on espère y trouver. L’astrobiologiste nous invite à participer à cette odyssée extraordinaire que nous vivons actuellement, et dont les images du télescope James-Webb ne sont qu’un infime reflet. Avec 300 millions d’exoplanètes dans la zone habitable de notre galaxie, penser que nous sommes seuls est une « absurdité statistique ». Dès lors nous sommes pris d’un vertige devant l’ampleur de certaines révélations. De Titan à la planète 55-Cancer-e, de l’équation de Drake au paradoxe de Fermi, des typologies de niveaux de civilisations extraterrestres à la théorie de Gaïa, c’est tout un monde inconnu qui s’ouvre à nous.
Un livre stimulant et accessible dans la lignée de Poussières d’étoiles de Hubert Reeves. Une invitation au voyage d’un nouveau genre, à la recherche d’une vie ailleurs dans l’Univers dont « l’absence de preuves n’est pas la preuve de l’absence », selon les mots de Carl Sagan.
Nathalie A. Cabrol est née à Bagneux en 1963. Astrobiologiste, elle dirige des projets de recherche pour la NASA depuis 1998, et a été nommée directrice scientifique du Centre de recherche Carl Sagan de l'Institut SETI en 2015. Elle raconte son parcours exceptionnel dans son premier livre, Voyage aux frontières de la vie (Seuil, 2021, Points, 2022).
Un livre stimulant et accessible dans la lignée de Poussières d’étoiles de Hubert Reeves. Une invitation au voyage d’un nouveau genre, à la recherche d’une vie ailleurs dans l’Univers dont « l’absence de preuves n’est pas la preuve de l’absence », selon les mots de Carl Sagan.
Nathalie A. Cabrol est née à Bagneux en 1963. Astrobiologiste, elle dirige des projets de recherche pour la NASA depuis 1998, et a été nommée directrice scientifique du Centre de recherche Carl Sagan de l'Institut SETI en 2015. Elle raconte son parcours exceptionnel dans son premier livre, Voyage aux frontières de la vie (Seuil, 2021, Points, 2022).
352 pages, Kindle Edition
Published January 6, 2023
184 people are currently reading
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About the author
Nathalie A. Cabrol
11 books46 followersFrench American astrobiologist specializing in planetary science. Cabrol studies ancient lakes on Mars, and undertakes high altitude scientific expeditions in the Central Andes of Chile as the Principal Investigator of the "High Lakes Project" funded by the NASA Astrobiology Institute (NAI). There, with her team, she documents life’s adaptation to extreme environments, the effect of rapid climate change on lake ecosystems and habitats, its geobiological signatures, and relevance to planetary exploration.
She is the Principal Investigator of the SETI Institute NAI team, which was selected in October 2014 to develop new biosignature detection and exploration strategies in support of the upcoming Mars 2020 mission. She was appointed in August 2015 to head the SETI Institute’s Carl Sagan Center for the Study of Life in the Universe.
She is the Principal Investigator of the SETI Institute NAI team, which was selected in October 2014 to develop new biosignature detection and exploration strategies in support of the upcoming Mars 2020 mission. She was appointed in August 2015 to head the SETI Institute’s Carl Sagan Center for the Study of Life in the Universe.
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Displaying 1 - 30 of 86 reviews
January 8, 2025
This was a nice summary of what we currently know about the plausibility of life in our solar system and beyond.
The author covers the plausibility that life exists or had existed on planets such as Mercury, Venus and Mars, planetoids such as Pluto and Ceres, moons such as Europa, Titan, Enceladus, Ganymede and others.
She covers the flyby, orbital and surface missions to these worlds and what they revealed as well as upcoming ground & spaceborne telescopes and space probes that will discover these worlds over the next decade and what they should reveal in terms of astrobiology.
Exoplanets and the fascinating methods that astronomers use to find them are also discussed. It is fascinating at how technology today can detect things of such low sensitivity (such as brightness variations of just 1/10,000th magnitude) millions or even billions of light years away.
There is an overview of the Drake Equation and what we know about its components so far, explanations for the Fermi Paradox and different classifications methodologies for the stages of civilization (Kardashev, Zubrin, Sagan, Barrow).
The book concludes with a rundown of what SETI is and isn't and the author's personal reflections and thoughts on the future of astrobiology, especially the involving of near future tech such as AI and autonomous robots and the biggest question of all, how exactly do we define life?
I felt the conclusive parts of the book (about 20%) were pretty weak as the author tries to inspire awe and wonder and issue a rallying call against self destruction of humanity. Which could have worked if the author had the literacy skills of Carl Sagan, but she does not.
The rest of the book where the author takes us through a tour of the potential habitable worlds, experiments, technology used, concepts and the functioning of SETI is fantastic and it feels very comprehensive.
It is a very accessible book free of any scientific jargon or deep technical dives. Another one of those perfect gift ideas to 13 year olds to get them interested in science.
The author covers the plausibility that life exists or had existed on planets such as Mercury, Venus and Mars, planetoids such as Pluto and Ceres, moons such as Europa, Titan, Enceladus, Ganymede and others.
She covers the flyby, orbital and surface missions to these worlds and what they revealed as well as upcoming ground & spaceborne telescopes and space probes that will discover these worlds over the next decade and what they should reveal in terms of astrobiology.
Exoplanets and the fascinating methods that astronomers use to find them are also discussed. It is fascinating at how technology today can detect things of such low sensitivity (such as brightness variations of just 1/10,000th magnitude) millions or even billions of light years away.
There is an overview of the Drake Equation and what we know about its components so far, explanations for the Fermi Paradox and different classifications methodologies for the stages of civilization (Kardashev, Zubrin, Sagan, Barrow).
The book concludes with a rundown of what SETI is and isn't and the author's personal reflections and thoughts on the future of astrobiology, especially the involving of near future tech such as AI and autonomous robots and the biggest question of all, how exactly do we define life?
I felt the conclusive parts of the book (about 20%) were pretty weak as the author tries to inspire awe and wonder and issue a rallying call against self destruction of humanity. Which could have worked if the author had the literacy skills of Carl Sagan, but she does not.
The rest of the book where the author takes us through a tour of the potential habitable worlds, experiments, technology used, concepts and the functioning of SETI is fantastic and it feels very comprehensive.
It is a very accessible book free of any scientific jargon or deep technical dives. Another one of those perfect gift ideas to 13 year olds to get them interested in science.
December 17, 2024
This is such an interesting book for what it proposes to achieve and not only by repeating the same old pattern of books based on Fermi's Paradox. About this, throughout the book, Nathalie A. Cabrol does use the terms "life as we know it" and "life as we might not know it", which is a much more reasonable way to talk about life in the cosmos, rather than pretend we are the sole species. We are not even the sole species, because there are thousands of species on planet Earth alone, but as long as we insist on claiming that life as we know it must have a consciousness like ours that might have evolved into a technological society like ours, then, it becomes quite hard to discuss the meaning of life in the cosmos.
To avoid it, Cabrol starts by explaining how life might have evolved on planet Earth with microscopic organisms, or microbes, that left behind signals in rocks about 3.7 billion years old, and how life evolved from then on. She then introduces us to the possibilities of the existence of life on the solar system planets and some of their moons, and from then on, to the cosmos, highlighting the kinds of life and civilizations there might be all around the universe, but also pointing out the reasons why we might not have yet found any signs of it. It is always an intelligent approach and not only a pretentious final word as some scientists tend to do these days.
Good and intelligent books like this keep me interested in reading scientific books.
To avoid it, Cabrol starts by explaining how life might have evolved on planet Earth with microscopic organisms, or microbes, that left behind signals in rocks about 3.7 billion years old, and how life evolved from then on. She then introduces us to the possibilities of the existence of life on the solar system planets and some of their moons, and from then on, to the cosmos, highlighting the kinds of life and civilizations there might be all around the universe, but also pointing out the reasons why we might not have yet found any signs of it. It is always an intelligent approach and not only a pretentious final word as some scientists tend to do these days.
Good and intelligent books like this keep me interested in reading scientific books.
June 19, 2024
we may wish to continue ignoring our downward spiral of self-destruction, in which case, the outcome is already determined. as we completely relinquish our survival instinct, we will not only sacrifice an entire biosphere, but also, most extraordinarily for any species, our own kind.in the secret life of the universe, french-american astrobiologist nathalie cabrol — director of the seti institute's carl sagan center — offers a thrilling, enlightening course on the current science of the search for life beyond earth. cabrol explores the latest theories on life's origins and the promising new discoveries that bring us collectively closer to finding it elsewhere. covering an expanse of subjects likely familiar to readers of general science, cabrol communicates with clarity and obvious passion. importantly, cabrol places the search for life beyond earth within the context of humanity's present and increasingly perilous moment on earth, urgently entreating us to correct course, re-engage with our planetary roots, and take better care of "our vessel in space."
July 2, 2025
Fascinating concept, horrible execution.
The author of The Secret Life of the Universe, Nathalie Cabrol, is the current head of the SETI Institute’s NASA Astrobiology Institute’s team. In astrobiology terms, from what I can tell, that more or less makes her the president of knowing what’s up with the potential for life beyond our planetary borders.
I figured, then, that this book would be a boundary-pushing treat: what new and interesting avenues are astrobiologists exploring? What kinds of strange planets and chemistries might host life that we could never imagine? How might that life look, communicate, and be perceived by those of us here on Earth? And to give her credit, Cabrol does try to touch on all of these points.
But that’s maybe the problem: the actual text of the book is only a little over 250 pages, and Cabrol is trying to cram (what seems to be) every current discussion or controversy or theory in her field into this space, while also introducing her reader to the basics of biological chemistry and geology. This results in a book that is dry, matter-of-fact, and only just manages to skim the surface of the topics covered. So many chapters or subsections end with Cabrol posing an interesting question or dilemma, only to leave it as some kind of exercise for the reader. I’m sure part of this is an effort to retain professionalism and credibility within her own position, but Cabrol’s text is sorely lacking in imagination, uninterested in pushing the envelope just a bit further.
The book also needed an additional round of editing. The grammar is at times sloppy and all over the place, and Cabrol often includes side-by-side sentences that say the same thing, just slightly reworded. Paragraphs of information are repeated within chapters. It’s just not a fun experience to read, something that I found profoundly disappointing.
And then the final nail in the coffin: Cabrol’s half-assed and hypocritical attempts at linking all of her work back to the climate crisis.
She spends half of the chapters preceding this final point salivating over innovations in AI and private-sector scientific ventures like Neuralink or SpaceX, nearly all of which are funded by money-hungry and resource-hoarding billionaires. And then she spins around and blames individual-level choices and overpopulation for climate change! Hm! Okay! She also makes this extremely counterintuitive comment about how “group selection” and the “preservation of future generations” might foster a kind of transhumanist altruism in the future, only to write extensively about how weird it is that we, as a species, are driving ourselves off of a cliff. Let’s think about that for a second, Nathalie. (Ironically, a compelling argument in favor of the discrediting of group selection theories.) All of this is also naturally written without a single nod to capitalist drivers of climate change, or even one single solution beyond maybe, like, biking to work every once in a while.
Womp womp.
The author of The Secret Life of the Universe, Nathalie Cabrol, is the current head of the SETI Institute’s NASA Astrobiology Institute’s team. In astrobiology terms, from what I can tell, that more or less makes her the president of knowing what’s up with the potential for life beyond our planetary borders.
I figured, then, that this book would be a boundary-pushing treat: what new and interesting avenues are astrobiologists exploring? What kinds of strange planets and chemistries might host life that we could never imagine? How might that life look, communicate, and be perceived by those of us here on Earth? And to give her credit, Cabrol does try to touch on all of these points.
But that’s maybe the problem: the actual text of the book is only a little over 250 pages, and Cabrol is trying to cram (what seems to be) every current discussion or controversy or theory in her field into this space, while also introducing her reader to the basics of biological chemistry and geology. This results in a book that is dry, matter-of-fact, and only just manages to skim the surface of the topics covered. So many chapters or subsections end with Cabrol posing an interesting question or dilemma, only to leave it as some kind of exercise for the reader. I’m sure part of this is an effort to retain professionalism and credibility within her own position, but Cabrol’s text is sorely lacking in imagination, uninterested in pushing the envelope just a bit further.
The book also needed an additional round of editing. The grammar is at times sloppy and all over the place, and Cabrol often includes side-by-side sentences that say the same thing, just slightly reworded. Paragraphs of information are repeated within chapters. It’s just not a fun experience to read, something that I found profoundly disappointing.
And then the final nail in the coffin: Cabrol’s half-assed and hypocritical attempts at linking all of her work back to the climate crisis.
She spends half of the chapters preceding this final point salivating over innovations in AI and private-sector scientific ventures like Neuralink or SpaceX, nearly all of which are funded by money-hungry and resource-hoarding billionaires. And then she spins around and blames individual-level choices and overpopulation for climate change! Hm! Okay! She also makes this extremely counterintuitive comment about how “group selection” and the “preservation of future generations” might foster a kind of transhumanist altruism in the future, only to write extensively about how weird it is that we, as a species, are driving ourselves off of a cliff. Let’s think about that for a second, Nathalie. (Ironically, a compelling argument in favor of the discrediting of group selection theories.) All of this is also naturally written without a single nod to capitalist drivers of climate change, or even one single solution beyond maybe, like, biking to work every once in a while.
Womp womp.
July 2, 2024
Thank you to the publisher for sending an arc for a review!! I’m so excited to dive into this book! I love astrobiology! Are we alone?
I have skimmed through the book so I could put out a review and I love the way it is broken down and the way the book reads! I love the pictures throughout the book as well!
I know this is going to be such an amazing read where I am going to learn a lot from!
Again, thank you so much for sending me an arc!! I will be coming back soon with a more in depth review after I completely read it.
I have skimmed through the book so I could put out a review and I love the way it is broken down and the way the book reads! I love the pictures throughout the book as well!
I know this is going to be such an amazing read where I am going to learn a lot from!
Again, thank you so much for sending me an arc!! I will be coming back soon with a more in depth review after I completely read it.
March 23, 2025
The book markets itself as being about the search for other life in the universe, but really, some of the most interesting stuff is about how we think life might have happened here.
The author is soundly on the side of “statistically speaking, there’s got to be something out there besides us,” but she also spends a lot of time talking about the vast comedy of errors required for life on Earth, and therefore the vast comedy of errors that would also have to happen elsewhere, assuming (and she goes into this too) any life that’s out there remotely resembles life as we’d recognize it.
There were once three planets in our own solar system in the habitable zone where liquid surface water is possible, she notes. Things changed. We were the lucky winners that didn’t freeze or boil.
I had no idea that the moon was so critical to Earth habitability. Now I do.
She also talks a lot about how the idea of “habitability” has changed and evolved.
There are parts that could have maybe used a more ruthless editor (especially near the end, where she’s got a narrative that she’s obviously passionate about, but that results in her saying the same thing in a couple of different ways over and over again).
Overall though, I’m glad I read it. And I would recommend it to anyone who wants to write sci-fi. The discussion of habitability and our best guess of what would be required for another technologically advanced civilization to form, and what first contact might look like and where we ourselves are investing in the search for other life, all offers a lot of story inspiration.
The author is soundly on the side of “statistically speaking, there’s got to be something out there besides us,” but she also spends a lot of time talking about the vast comedy of errors required for life on Earth, and therefore the vast comedy of errors that would also have to happen elsewhere, assuming (and she goes into this too) any life that’s out there remotely resembles life as we’d recognize it.
There were once three planets in our own solar system in the habitable zone where liquid surface water is possible, she notes. Things changed. We were the lucky winners that didn’t freeze or boil.
I had no idea that the moon was so critical to Earth habitability. Now I do.
She also talks a lot about how the idea of “habitability” has changed and evolved.
There are parts that could have maybe used a more ruthless editor (especially near the end, where she’s got a narrative that she’s obviously passionate about, but that results in her saying the same thing in a couple of different ways over and over again).
Overall though, I’m glad I read it. And I would recommend it to anyone who wants to write sci-fi. The discussion of habitability and our best guess of what would be required for another technologically advanced civilization to form, and what first contact might look like and where we ourselves are investing in the search for other life, all offers a lot of story inspiration.
October 25, 2025
The intangible romance and magic of the universe will always fascinate me. When I can learn about subjects on the cosmic scale, or the intricate, unseen networks of the minute, I am struck by how much we know, and yet how little it seems to matter. We live in an age when the sum of human knowledge is immense, yet the meaning of it feels diminished. We have compressed existence into what is immediately relevant to us, confined by our own urgency to achieve, to succeed, to matter. This is the hypermodern state of being we find ourselves in. A life defined by self-imposed immediacy.
Of course, we cannot control what is important to us. We live short, complicated lives that are rightfully unconcerned with the scale of the universe. But it is in these rare moments of cosmic reflection that my existence feels most profound. That throughout the entire known universe, we could be the sole living observers of reality. Existence is only recognized because we perceive it. Purpose is only recognized because we imagine it. And most importantly, beauty is only recognized by us.
If a tree falls in a forest and nobody hears it, did it make a sound? Without a conscious observer, I’d argue no. If beauty exists and no one is around to admire it, is it really beautiful? There lies our purpose, our duty, our responsibility. The countless wonders of this world are ours alone to witness. Billions of years have passed, and trillions will likely follow, but only now, and here, they meet your eyes. Take this time now to admire the show the universe has spent eons perfecting, culminating at this singular instant, specifically for you.
Of course, we cannot control what is important to us. We live short, complicated lives that are rightfully unconcerned with the scale of the universe. But it is in these rare moments of cosmic reflection that my existence feels most profound. That throughout the entire known universe, we could be the sole living observers of reality. Existence is only recognized because we perceive it. Purpose is only recognized because we imagine it. And most importantly, beauty is only recognized by us.
If a tree falls in a forest and nobody hears it, did it make a sound? Without a conscious observer, I’d argue no. If beauty exists and no one is around to admire it, is it really beautiful? There lies our purpose, our duty, our responsibility. The countless wonders of this world are ours alone to witness. Billions of years have passed, and trillions will likely follow, but only now, and here, they meet your eyes. Take this time now to admire the show the universe has spent eons perfecting, culminating at this singular instant, specifically for you.
September 2, 2024
Described on the cover as 'An Astrobiologist's Search for the Origins and Frontiers of Life', this is a thoughtful, well-constructed and eminently readable book that takes us on a journey not only through the solar system and beyond, but through the way our knowledge and understanding of 'life' has changed and matured over the last few decades.
And it also asks the question of 'what is life?', recognising that we really need to know what we're looking for if we're going to go looking for it!
For anyone interested in astrobiology, and the really, really big questions of the universe, this is a book worth reading.
And it also asks the question of 'what is life?', recognising that we really need to know what we're looking for if we're going to go looking for it!
For anyone interested in astrobiology, and the really, really big questions of the universe, this is a book worth reading.
September 14, 2024
TITLE: THE SECRET LIFE OF THE UNIVERSE
AUTHOR: NATHALIE A CABROL
PUB DATE: 08.13.2024
One of the world’s leading astrobiologists takes us on an awe-inspiring journey across the cosmos to investigate some of humanity’s most profound questions: Are we alone in the universe? And, how did life on Earth begin?
THOUGHTS:
I love how Cabrol illuminated the study of astronomy, and life on Earth and beyond truly accessible and a captivating read that was enjoyable, exhilarating, and Wonderful.
AUTHOR: NATHALIE A CABROL
PUB DATE: 08.13.2024
One of the world’s leading astrobiologists takes us on an awe-inspiring journey across the cosmos to investigate some of humanity’s most profound questions: Are we alone in the universe? And, how did life on Earth begin?
THOUGHTS:
I love how Cabrol illuminated the study of astronomy, and life on Earth and beyond truly accessible and a captivating read that was enjoyable, exhilarating, and Wonderful.
May 13, 2025
I’ve always had curiosity for the field of astrobiology. So much so that in the past I’ve taken some free online courses on exoplanets and extremophiles. Nevertheless, I have learned so much from this book. The author clearly knows what she is talking about and she does a great job at explaining everything from different theories on the origin of life, definitions of what constitutes living and non-living things, and potential scenarios where life could have arisen in our solar system and beyond. The author’s passion for astrobiology is contagious and I thoroughly enjoyed this book.
January 16, 2023
Une lecture intéressante, mais que je n'ai pas trouvé facile surtout au début, où il faut se familiariser avec le vocabulaire scientifique. L'objet livre est superbe et les informations sont passionnantes pour notamment en découvrir plus sur les planètes du système solaire, explorer la viabilité sur Mars ou Venus, mais surtout comprendre où en sont les recherches pour d'autres formes de vie.
December 29, 2024
The meaning of Life itself is a debatable topic. With very little understanding on what life is, humans have been curious about life elsewhere. The origins of of Life is still a mystery to us and there are so many theories about how life emerged on earth. The field of Astrobiology in itself is still in its primitive age and the exploration of exoplanets are making way for astrobiology to grow and study various environments in which life could emerge. There are thousands of planet in our galaxy alone that are similar to earth that could harbour life as we know it and millions more that could harbour life in ways we wouldn’t even expect it to be. Encountering an alien lifeform is not too distant in our future may it be microbial or intelligent life like us or something too advance even for our understanding. This book is a good introduction to get to know about the theories and findings surrounding life elsewhere!
January 22, 2025
A thoroughly detailed journey through all the prospective locations for extraterrestrial life currently being researched. From the cloud layers of Venus to the sub-surface of Pluto. From the hydrocarbon lakes of Titan to the whole galaxy. Cabrol eloquently explains the habitability of numerous locations, providing context and scope for sure missions. This book also poignantly explores our place in the universe, and our responsibility to our planet and our species.
March 29, 2025
Know thyself. What is life, where is it taking us, what is our destiny? Studying the origin of life, here on earth and elsewhere in the universe tells us how fragile it is. Small as well as catastrophic changes make a difference. As we look to the future horizons, as ancient mariners did, we need to maintain our vessel spaceship earth. It is what will get use there. Through testing belief (theorem) by gaining knowledge we get closer to understanding the truth. The sharing of theory and having it confirmed or denied gives us knowledge we can use for the greater good of all of humanity.
My most recent Earthrise moment came on Spring equinox when walking my dog at sunrise. The last quarter moon was straight ahead to the south, backgrounded in the dark sky, and the first rose rays of sun rise was to my left in the east. In contemplating orbital mechanics impressed the reality that we are indeed space travelers. My thoughts turn to the stewardship God gave us, how we were made in his image and how to know him by understanding life, his universe through the pursuit of knowledge and thus becoming participants in the stewardship of starship earth.
My most recent Earthrise moment came on Spring equinox when walking my dog at sunrise. The last quarter moon was straight ahead to the south, backgrounded in the dark sky, and the first rose rays of sun rise was to my left in the east. In contemplating orbital mechanics impressed the reality that we are indeed space travelers. My thoughts turn to the stewardship God gave us, how we were made in his image and how to know him by understanding life, his universe through the pursuit of knowledge and thus becoming participants in the stewardship of starship earth.
May 7, 2025
I find this topic very interesting so 5 out of 5 stars would seem to be a self fulfilling prophecy but this book is really well written. The flow is perfect and it really grabbed my attention. The author’s connections to other scientists and their subsequent interaction really adds to the narrative.
April 27, 2025
Very repetitive, I couldn't finish after 80 percent. Only topic talked about is my least favorite part about the universe. Listening to the humans options to colonize the universe for 9 hours was boring.
June 12, 2025
Seems inevitable that life is out there. It’s not as much a matter of where - but when.
August 5, 2025
4.5
The first hard science nonfiction book I’ve ever attempted, and I had a great time. Breezed through it thanks to Cabrol’s accessible writing style (which is not to say that I understood everything I read), her contagious excitement for the topic, the book’s short chapter lengths, and its repetition of key concepts to the point of helpfulness, not redundancy.
Developing my interest in outer space is a long-term project. I’ve always preferred nonfiction that delves into the soft sciences and, if I must explore nature, the oceans and trees are my go-to. But adoring Martin MacInnes’ “In Ascension” (2023) as much as I did has spurred a thirst for knowledge about worlds beyond our own that I plan to exploit for as long as it lasts. Finding this hardcover in exquisite condition for half-price at a local used bookstore felt like a great start.
In her introduction, Cabrol hints toward the slower pace at which man’s conception of life and our place in the universe has changed relative to the sheer number of scientific breakthroughs that have emerged over the past few decades. The paradigmatic shifts taking place today concerning the very definition of life and its potential extraterrestrial discovery have yet to shock the public. “We are both the observer and the observation; we are life trying to understand itself and its origins” [p. 5], she adds as a kind of explanation: naturally, some collective skepticism is to be expected. I went into this work wondering if it would fundamentally change my own preconceptions of life and the universe, and I believe it has.
Defining Life:
Cabrol’s interrogations into the definition of “life” are some of the most memorable parts of this book. General consensus is that life’s building blocks are the elements carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulphur (CHNOPS) [p. 14], but both our own world and worlds beyond reveal far greater complexity hidden beneath the surface, literally and figuratively.
Firstly, how such elements came to reside on Earth is still being researched: one theory attributes the source of phosphorus, for instance, to an asteroid or comet that collided with Earth in the distant past [p. 16]. While carbon is most strongly associated with the potential for life (with sulphur following as a close second) [p. 83], even on our own planet, conditions exist that continually defy our understanding of the chemistry of life (think: hydrothermal vents and marine/continental subsurfaces). One fascinating concept is the Shadow Biosphere: hypothetical environments/ecosystems on our planet based on entirely different molecular biochemistry than that which we typically recognize as life-sustaining [p. 43]. If we modify our definition of life even slightly, Cabrol suggests, it could expand to include a vast spectrum of lifeforms we might not otherwise consider living.
Throughout her work, the author distinguishes between “life as we know it” and “life as we do not know it.” If “aliens” do exist in our solar system, they are unlikely to be the humanoid, bipedal creatures of our popular imagination. Rather, they’ll take the form of microbes detected hundreds of kilometers deep in icy oceans. Or, even more likely, they’ll exist in ways we may be entirely unable to detect if we do not explore creatively what it means to be alive.
Interestingly, the book does not explore “official” narratives until its final chapter. Here, Cabrol cites NASA’s definition of life as “a self-sustaining chemical system capable of Darwinian evolution” [p. 239], Edward Trifonov’s “an almost exact self-reproduction with variations,” and Alexander Oparin’s “any system capable of replication and mutation” [p. 240]. She also acknowledges the Gaia theory: the idea that all living organisms and their environments are constantly seeking life-sustaining equilibrium. To me, the overlap lies in intent: to live is to attempt to survive the conditions into which you were born.
And in that regard, we have only one frame of reference: Earth. Of course, creatures at home have challenged the life-death binary for as long as we have been around to observe them. (Shortly after finishing this book, I listened to Alie Ward’s “Ologies” episode on Tardigradology featuring Dr. Paul Bartels. Tardigrades are a fitting example of the limits to our definition of life, thanks to their ability to “sleep” in a state of cryptobiosis for undetermined lengths of time.) Yet even more fundamental questions abound: how long does it take basic scattered organic molecules to turn into biology, or “life”? [p. 148] We’ve been able to simulate complex molecule formation in labs, but we cannot yet “create” life from scratch. The discovery of extraterrestrial lifeforms would be just as groundbreaking for what they could teach us about defining life as for the opportunity to speculate on the origin stories of alien ecosystems.
Life’s Origins:
Of course, how we define life dictates the way we theorize on its origins.
One such proposal, Panspermia, theorizes that life did not originate on Earth but is floating around in space dust and is being deposited, via asteroids and comets, upon various planets including our own. Scientists remain unconvinced by Panspermia because it fails to sufficiently account for the logistics of travel: How likely is it that an organism would survive displacement from its birthplace? How could it possibly withstand the long journey through space? And what are the odds it would adapt successfully to an entirely new planet? Moreover, while Panspermia may “explain” how life arrived on Earth, it fails to theorize how it emerged in space to begin with. [p. 33-35]
As an alternative, Cabrol introduces Alexander Oparin’s biochemical model for the origin of life:
I find this idea utterly fascinating: life as the logical outcome to evolution; life, an innate desire for survival, as the key ingredient to achieving chemical equilibrium on Earth.
In fact, I’d argue we already evaluate life in such terms, philosophically speaking at least. Our judgement of civilizations as “developed” or “underdeveloped” is intrinsically tied to the extent to which their members have been able to harness the natural environment for maximum efficiency. Walter Rodney explains this best in “How Europe Underdeveloped Africa”:
As such, would our progression from stone to metal; or hunting/gathering to farming/herding; or nomadism to specialization constitute evolutionary development? Perhaps not from a biological standpoint – and, for obvious reasons, I hesitate to apply the language of species differentiation in the animal kingdom to human beings – but I find the argument interesting to ponder from a cultural/anthropological perspective.
Cabrol’s book itself explores the concept of civilization in greater depth than I would have expected. She points out that worlds less hospitable than our Earth might “generate different [styles] of coevolution of life and environment” [p. 201], a fact that felt entirely too obvious only once it had been pointed out to me: of course, the less predictable a world is, the less power its inhabitants will have to assert their dominance over it. What could this mean for our potential to, in the far distant future, colonize new worlds? Advanced development on Earth could equate to extreme underdevelopment on, say, TRAPPIST-ie, which Cabrol describes as “the closest planet to Earth 2.0 we have found so far” [p. 186].
In defining civilization, too, scientists are divided. Various models have been proposed for classifying the development of civilizations, all of which evaluate our place upon them as a united species, 8 billion strong. On the one hand, scientists like Nikolai Kardashev distinguish between possible stages of civilization by how their members utilize energy [p. 212]:
Type I: those able to manipulate the energy available on its planet;
Type II: those able to manipulate the energy of its planetary system;
Type III: those able to manipulate the energy of its galaxy.
Others like John Barrow invert this scale, depicting development instead as the extent to which civilizations are able to manipulate their environment at increasingly small scales [p. 215]:
Type I: those able to manipulate like-sized objects;
Type II: those able to manipulate genes;
Type III: those able to manipulate molecules;
Type IV: those able to manipulate atoms;
Type V: those able to manipulate protons;
Type VI: those able to manipulate quarks;
Type Omega: those able to manipulate space and time.
If extraterrestrial advanced civilizations do exist, and I am incorrect in my assumption that alternate life is only conceivable in the form of minuscule organisms, Cabrol suggests that the aggressive nature of the human species may be echoed across the universe. Perhaps one indicator of development is the capacity to enact war and, thus, we are destined to destroy ourselves before ever making first contact [p. 208]. This perspective feels both uninspired and impossible to ignore given our species’ inclination towards mass-violence since time immemorial. The fact that the war in Ukraine has delayed a European mission to Mars since 2022 only strengthens this argument [p. 73]. (Note: Cabrol discusses various perspectives on the Great Filter and Rare Earth Paradox throughout pages 202 and 203.)
Other concepts tying civilization to space exploration include transhumanism – the enhancement of the human species through technology designed to elongate life span (think: cyborgs) [p. 246] – and urban development. In one passage I particularly enjoyed, Cabrol likens the complexity of language and genetic code to the scale of megacities, acting themselves like complex cells in which energy is harnessed and redistributed, membranes are constructed and breached, and organelles (people, communities, neighborhoods) function symbiotically to keep the entire machine running [p. 249].
Life Elsewhere:
So, where might we find extraterrestrial life?
First of all, it was news to me that entire oceans are believed to rest under the frozen crusts of Saturn’s moon Enceladus or Jupiter’s Europa and Ganymede. Oceans under ice. How incredible to imagine that living organisms inhabiting these environments may be entirely closed off from the atmosphere above the crust and that this impenetrability might, in some cases, be essential to their survival!
This discovery strengthens my appreciation for the fact that our own atmosphere was once inhospitable to life. Through both Cabrol’s book and Alie Ward’s “Ologies” episode on Macrophycology (this podcast never misses), I learned that were it not for the development of algae left alone to photosynthesize for several hundred million years, we would not have a viable atmosphere in which to survive today [p. 19]. Of course, it took billions of years for algae to form thanks to the consumption of a cyanobacterium by a single cell Eukaryote. Cyanobacteria would eventually evolve into chloroplast with the capacity to transform light and carbon dioxide into sugars and oxygen.
Speaking of atmospheres, this book has enriched my conception of “rain” in ways I was not expecting. On Saturn’s Titan for example, organic compounds are believed to fall freely on the moon’s surface through precipitation, eventually making their way to the ocean floor where they accumulate as sediment. (An alternative, bottom-up theory posits Titan’s core as containing organic compounds originating from the Oort Cloud and integrated into the moon’s composition during its early formation; such compounds may eventually make their way upwards into Titan’s oceans) [p. 124]. In either case, these processes increase the potential for life on Titan.
Similarly, Pluto’s atmosphere is full of tholins (i.e., organic molecules) that get trapped in a cycle of rising and falling back onto its surface (which, by the way, is how Pluto gets its pretty red splotches). In the summer, when its atmosphere expands, some of those tholins actually leave the dwarf planet, travel through space, and settle on its moon Charon, which is also why Charon has an orange-y tint to its North Pole. [p. 139]
Cabrol’s chapter on Mars has lingered with me for its philosophical thrust: at what point do we consider ourselves a species invasive to worlds beyond our Earth? The author identifies an indeterminate deadline limiting our exploration of Martian lifeforms: the arrival of the first humans on the planet. She writes:
And yet, shortly thereafter, she explores the theory that we ourselves may be “natives” to the Red Planet. Given Mars’ position relative to our Earth, both physically and developmentally, life on Mars may have emerged 100 million years before it did on Earth. Moreover, some theorists propose, life on Earth may have originated on Mars [p. 90]. Does the fact that we may be “Martians” justify eventually settling the planet? I remain skeptical.
My own complex feelings regarding space exploration aside, Cabrol returns to this message at the end of her book, justifying man’s desire to make contact with our “galactic family” on the basis of our origins as stardust [p. 211]. The book’s epilogue delivers a rather preachy, yet necessary, warning against impending climate doom on Earth, leaving no room for doubt that, while we may be that much closer to discovering habitable environments elsewhere, our technology is nowhere near what would be required to support life sustainably on a new planet. Cabrol’s message is simple and indisputable: if we wish to learn more about the universe around us, we must first take care of that which we now call home.
The first hard science nonfiction book I’ve ever attempted, and I had a great time. Breezed through it thanks to Cabrol’s accessible writing style (which is not to say that I understood everything I read), her contagious excitement for the topic, the book’s short chapter lengths, and its repetition of key concepts to the point of helpfulness, not redundancy.
Developing my interest in outer space is a long-term project. I’ve always preferred nonfiction that delves into the soft sciences and, if I must explore nature, the oceans and trees are my go-to. But adoring Martin MacInnes’ “In Ascension” (2023) as much as I did has spurred a thirst for knowledge about worlds beyond our own that I plan to exploit for as long as it lasts. Finding this hardcover in exquisite condition for half-price at a local used bookstore felt like a great start.
In her introduction, Cabrol hints toward the slower pace at which man’s conception of life and our place in the universe has changed relative to the sheer number of scientific breakthroughs that have emerged over the past few decades. The paradigmatic shifts taking place today concerning the very definition of life and its potential extraterrestrial discovery have yet to shock the public. “We are both the observer and the observation; we are life trying to understand itself and its origins” [p. 5], she adds as a kind of explanation: naturally, some collective skepticism is to be expected. I went into this work wondering if it would fundamentally change my own preconceptions of life and the universe, and I believe it has.
Defining Life:
Cabrol’s interrogations into the definition of “life” are some of the most memorable parts of this book. General consensus is that life’s building blocks are the elements carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulphur (CHNOPS) [p. 14], but both our own world and worlds beyond reveal far greater complexity hidden beneath the surface, literally and figuratively.
Firstly, how such elements came to reside on Earth is still being researched: one theory attributes the source of phosphorus, for instance, to an asteroid or comet that collided with Earth in the distant past [p. 16]. While carbon is most strongly associated with the potential for life (with sulphur following as a close second) [p. 83], even on our own planet, conditions exist that continually defy our understanding of the chemistry of life (think: hydrothermal vents and marine/continental subsurfaces). One fascinating concept is the Shadow Biosphere: hypothetical environments/ecosystems on our planet based on entirely different molecular biochemistry than that which we typically recognize as life-sustaining [p. 43]. If we modify our definition of life even slightly, Cabrol suggests, it could expand to include a vast spectrum of lifeforms we might not otherwise consider living.
Throughout her work, the author distinguishes between “life as we know it” and “life as we do not know it.” If “aliens” do exist in our solar system, they are unlikely to be the humanoid, bipedal creatures of our popular imagination. Rather, they’ll take the form of microbes detected hundreds of kilometers deep in icy oceans. Or, even more likely, they’ll exist in ways we may be entirely unable to detect if we do not explore creatively what it means to be alive.
Interestingly, the book does not explore “official” narratives until its final chapter. Here, Cabrol cites NASA’s definition of life as “a self-sustaining chemical system capable of Darwinian evolution” [p. 239], Edward Trifonov’s “an almost exact self-reproduction with variations,” and Alexander Oparin’s “any system capable of replication and mutation” [p. 240]. She also acknowledges the Gaia theory: the idea that all living organisms and their environments are constantly seeking life-sustaining equilibrium. To me, the overlap lies in intent: to live is to attempt to survive the conditions into which you were born.
And in that regard, we have only one frame of reference: Earth. Of course, creatures at home have challenged the life-death binary for as long as we have been around to observe them. (Shortly after finishing this book, I listened to Alie Ward’s “Ologies” episode on Tardigradology featuring Dr. Paul Bartels. Tardigrades are a fitting example of the limits to our definition of life, thanks to their ability to “sleep” in a state of cryptobiosis for undetermined lengths of time.) Yet even more fundamental questions abound: how long does it take basic scattered organic molecules to turn into biology, or “life”? [p. 148] We’ve been able to simulate complex molecule formation in labs, but we cannot yet “create” life from scratch. The discovery of extraterrestrial lifeforms would be just as groundbreaking for what they could teach us about defining life as for the opportunity to speculate on the origin stories of alien ecosystems.
Life’s Origins:
Of course, how we define life dictates the way we theorize on its origins.
One such proposal, Panspermia, theorizes that life did not originate on Earth but is floating around in space dust and is being deposited, via asteroids and comets, upon various planets including our own. Scientists remain unconvinced by Panspermia because it fails to sufficiently account for the logistics of travel: How likely is it that an organism would survive displacement from its birthplace? How could it possibly withstand the long journey through space? And what are the odds it would adapt successfully to an entirely new planet? Moreover, while Panspermia may “explain” how life arrived on Earth, it fails to theorize how it emerged in space to begin with. [p. 33-35]
As an alternative, Cabrol introduces Alexander Oparin’s biochemical model for the origin of life:
The first modern biochemical model for the origin of life [suggests] that life arose gradually from inorganic molecules, building blocks like amino acids forming first. They then combined to make complex polymers in warm pools at the water’s edge. Oparin did not see any fundamental differences between a living organism and lifeless matter. He thought that the characteristics of life had arisen as part of the evolution of matter. In other words, prebiotic chemistry transitioned to biology. [p. 35]
I find this idea utterly fascinating: life as the logical outcome to evolution; life, an innate desire for survival, as the key ingredient to achieving chemical equilibrium on Earth.
In fact, I’d argue we already evaluate life in such terms, philosophically speaking at least. Our judgement of civilizations as “developed” or “underdeveloped” is intrinsically tied to the extent to which their members have been able to harness the natural environment for maximum efficiency. Walter Rodney explains this best in “How Europe Underdeveloped Africa”:
More often than not, the term “development” is used in an exclusive economic sense—the justification being that the type of economy is itself an index of other social features. What then is economic development? A society develops economically as its members increase jointly their capacity for dealing with the environment. This capacity for dealing with the environment is dependent on the extent to which they understand the laws of nature (science), on the extent to which they put that understanding into practice by devising tools (technology), and on the manner in which work is organized. [Chapter I: Some Questions on Development]
As such, would our progression from stone to metal; or hunting/gathering to farming/herding; or nomadism to specialization constitute evolutionary development? Perhaps not from a biological standpoint – and, for obvious reasons, I hesitate to apply the language of species differentiation in the animal kingdom to human beings – but I find the argument interesting to ponder from a cultural/anthropological perspective.
Cabrol’s book itself explores the concept of civilization in greater depth than I would have expected. She points out that worlds less hospitable than our Earth might “generate different [styles] of coevolution of life and environment” [p. 201], a fact that felt entirely too obvious only once it had been pointed out to me: of course, the less predictable a world is, the less power its inhabitants will have to assert their dominance over it. What could this mean for our potential to, in the far distant future, colonize new worlds? Advanced development on Earth could equate to extreme underdevelopment on, say, TRAPPIST-ie, which Cabrol describes as “the closest planet to Earth 2.0 we have found so far” [p. 186].
In defining civilization, too, scientists are divided. Various models have been proposed for classifying the development of civilizations, all of which evaluate our place upon them as a united species, 8 billion strong. On the one hand, scientists like Nikolai Kardashev distinguish between possible stages of civilization by how their members utilize energy [p. 212]:
Type I: those able to manipulate the energy available on its planet;
Type II: those able to manipulate the energy of its planetary system;
Type III: those able to manipulate the energy of its galaxy.
Others like John Barrow invert this scale, depicting development instead as the extent to which civilizations are able to manipulate their environment at increasingly small scales [p. 215]:
Type I: those able to manipulate like-sized objects;
Type II: those able to manipulate genes;
Type III: those able to manipulate molecules;
Type IV: those able to manipulate atoms;
Type V: those able to manipulate protons;
Type VI: those able to manipulate quarks;
Type Omega: those able to manipulate space and time.
If extraterrestrial advanced civilizations do exist, and I am incorrect in my assumption that alternate life is only conceivable in the form of minuscule organisms, Cabrol suggests that the aggressive nature of the human species may be echoed across the universe. Perhaps one indicator of development is the capacity to enact war and, thus, we are destined to destroy ourselves before ever making first contact [p. 208]. This perspective feels both uninspired and impossible to ignore given our species’ inclination towards mass-violence since time immemorial. The fact that the war in Ukraine has delayed a European mission to Mars since 2022 only strengthens this argument [p. 73]. (Note: Cabrol discusses various perspectives on the Great Filter and Rare Earth Paradox throughout pages 202 and 203.)
Other concepts tying civilization to space exploration include transhumanism – the enhancement of the human species through technology designed to elongate life span (think: cyborgs) [p. 246] – and urban development. In one passage I particularly enjoyed, Cabrol likens the complexity of language and genetic code to the scale of megacities, acting themselves like complex cells in which energy is harnessed and redistributed, membranes are constructed and breached, and organelles (people, communities, neighborhoods) function symbiotically to keep the entire machine running [p. 249].
Life Elsewhere:
So, where might we find extraterrestrial life?
First of all, it was news to me that entire oceans are believed to rest under the frozen crusts of Saturn’s moon Enceladus or Jupiter’s Europa and Ganymede. Oceans under ice. How incredible to imagine that living organisms inhabiting these environments may be entirely closed off from the atmosphere above the crust and that this impenetrability might, in some cases, be essential to their survival!
This discovery strengthens my appreciation for the fact that our own atmosphere was once inhospitable to life. Through both Cabrol’s book and Alie Ward’s “Ologies” episode on Macrophycology (this podcast never misses), I learned that were it not for the development of algae left alone to photosynthesize for several hundred million years, we would not have a viable atmosphere in which to survive today [p. 19]. Of course, it took billions of years for algae to form thanks to the consumption of a cyanobacterium by a single cell Eukaryote. Cyanobacteria would eventually evolve into chloroplast with the capacity to transform light and carbon dioxide into sugars and oxygen.
Speaking of atmospheres, this book has enriched my conception of “rain” in ways I was not expecting. On Saturn’s Titan for example, organic compounds are believed to fall freely on the moon’s surface through precipitation, eventually making their way to the ocean floor where they accumulate as sediment. (An alternative, bottom-up theory posits Titan’s core as containing organic compounds originating from the Oort Cloud and integrated into the moon’s composition during its early formation; such compounds may eventually make their way upwards into Titan’s oceans) [p. 124]. In either case, these processes increase the potential for life on Titan.
Similarly, Pluto’s atmosphere is full of tholins (i.e., organic molecules) that get trapped in a cycle of rising and falling back onto its surface (which, by the way, is how Pluto gets its pretty red splotches). In the summer, when its atmosphere expands, some of those tholins actually leave the dwarf planet, travel through space, and settle on its moon Charon, which is also why Charon has an orange-y tint to its North Pole. [p. 139]
Cabrol’s chapter on Mars has lingered with me for its philosophical thrust: at what point do we consider ourselves a species invasive to worlds beyond our Earth? The author identifies an indeterminate deadline limiting our exploration of Martian lifeforms: the arrival of the first humans on the planet. She writes:
Once we set foot on Mars, it will only be a matter of time before the planet becomes contaminated. Humans are walking microbiomes and the environmental conditions on Mars might not be different enough to prevent some terrestrial microorganisms from adapting to a new planet. Humanity’s arrival will thus signal a permanent modification of the Martian environment, and we may bring life to a place that possibly never had it before. [p. 89]
And yet, shortly thereafter, she explores the theory that we ourselves may be “natives” to the Red Planet. Given Mars’ position relative to our Earth, both physically and developmentally, life on Mars may have emerged 100 million years before it did on Earth. Moreover, some theorists propose, life on Earth may have originated on Mars [p. 90]. Does the fact that we may be “Martians” justify eventually settling the planet? I remain skeptical.
My own complex feelings regarding space exploration aside, Cabrol returns to this message at the end of her book, justifying man’s desire to make contact with our “galactic family” on the basis of our origins as stardust [p. 211]. The book’s epilogue delivers a rather preachy, yet necessary, warning against impending climate doom on Earth, leaving no room for doubt that, while we may be that much closer to discovering habitable environments elsewhere, our technology is nowhere near what would be required to support life sustainably on a new planet. Cabrol’s message is simple and indisputable: if we wish to learn more about the universe around us, we must first take care of that which we now call home.
March 23, 2025
I really wanted to like this book but I felt like it was so lifeless (ironically enough). You can tell the author tried to throw in a joke here and there but most of the book is just straight facts presented in such a way that made me fall asleep. I thought maybe i just don’t like nonfiction, but I read two other nonfiction books so far this year and neither of them were as mind numbing as this one.
June 20, 2024
Thanks to @scribnerbooks for this ARC in exchange for a free and fair review. Wow! I never thought I would be reading a book about astrobiology but here we are. Cheers to Carbal, who wrote a science book that a humanities girl like myself could understand. I highly recommend stepping out of your comfort zone into a whole new world with “The Secreet Life of rhe Uniserve.” You won’t be sorry you did! I also loved Carbol’s immersive writing style and vivid imagery.
September 7, 2024
This book is written by the director of the Carl Sagan Institute, Dr. Nathalie A. Cabrol. Rather than dealing with speculative surmises about astrobiology, the focus of this book is detailed information about planetary geology-- the specific geomorphology, geological processes, and geological compositions of various candidate worlds for habitability within our solar system and beyond. The book then notes the conditions of habitability that may be supported in these worlds. It is packed with information and a true learning experience.
Some notes as follows:
-(Venus section) Some hypotheses for Venus' current hothouse state include: i) ocean evaporation due to increased solar luminosity, leading to suffusion of water vapor as a greenhouse gas, the death of plate tectonics, and a feedback loop; ii) magma oceans for a planet that never cooled; iii) the eruption of large igneous provinces (LIP) leading to mass release of CO2 and a runaway greenhouse
- (Mars section) loss of magnetization -> loss of atmosphere due to solar wind and radiation-> desertification
-(Moons as ocean worlds) interior energy sources such as radioactivity and tidal heating may lead to nutrient cycling within a fluid ocean
-(Callisto) tidally locked, behaves with electrical conductivity, clueing in on a salty ocean locked possibly 250 km below the surface
-(Ganymede) has a magnetic field, has aurorae, has aurorae that change directions which is indicative of a salty ocean located 150km subsurface, and 90 km deep (!), thus exceeding Earth oceans' depth by 10 times. It has a thin oxygen atmosphere and tidal heating with tectonic activity
-(Enceladus) 100% surface reflectivity, coldest Saturnian moon [-198 C], may have a porous core that allows heat cycling as warm water is heated by the core and rises, has plumes of geysers from hydrothermal energy
-(Europa) has global ocean 160km deep and 10-32 km below subsurface, an ice shell surface that is -160C meeting the inner ocean of 0C
-(Titan) has liquid methane rain, and possibly liquid methane lakes with water ice blocks for rocks. Titan possesses a hydrological cycle, or maybe properly referred to as a liquid methane-ological cycle, of rainstorms, pools in ponds and lakes, flows in streams and rivers of liquid methane. It has a huge sea aptly called Kraken Mare
-(Pluto) has glaciers of solid nitrogen
-(extreme exoplanets) WASP-12b is egg-shaped from sheer gravitational engulfing; 55 Cancri e is 2700C in temps and has a supercritical fluid state; Hoth is a galaxy-center planet with the coldest temperature of -220C; Kepler 22b is a super-Earth with a mega ocean; Kepler 78 b is a magma world
Highly recommend this beautiful book.
Some notes as follows:
-(Venus section) Some hypotheses for Venus' current hothouse state include: i) ocean evaporation due to increased solar luminosity, leading to suffusion of water vapor as a greenhouse gas, the death of plate tectonics, and a feedback loop; ii) magma oceans for a planet that never cooled; iii) the eruption of large igneous provinces (LIP) leading to mass release of CO2 and a runaway greenhouse
- (Mars section) loss of magnetization -> loss of atmosphere due to solar wind and radiation-> desertification
-(Moons as ocean worlds) interior energy sources such as radioactivity and tidal heating may lead to nutrient cycling within a fluid ocean
-(Callisto) tidally locked, behaves with electrical conductivity, clueing in on a salty ocean locked possibly 250 km below the surface
-(Ganymede) has a magnetic field, has aurorae, has aurorae that change directions which is indicative of a salty ocean located 150km subsurface, and 90 km deep (!), thus exceeding Earth oceans' depth by 10 times. It has a thin oxygen atmosphere and tidal heating with tectonic activity
-(Enceladus) 100% surface reflectivity, coldest Saturnian moon [-198 C], may have a porous core that allows heat cycling as warm water is heated by the core and rises, has plumes of geysers from hydrothermal energy
-(Europa) has global ocean 160km deep and 10-32 km below subsurface, an ice shell surface that is -160C meeting the inner ocean of 0C
-(Titan) has liquid methane rain, and possibly liquid methane lakes with water ice blocks for rocks. Titan possesses a hydrological cycle, or maybe properly referred to as a liquid methane-ological cycle, of rainstorms, pools in ponds and lakes, flows in streams and rivers of liquid methane. It has a huge sea aptly called Kraken Mare
-(Pluto) has glaciers of solid nitrogen
-(extreme exoplanets) WASP-12b is egg-shaped from sheer gravitational engulfing; 55 Cancri e is 2700C in temps and has a supercritical fluid state; Hoth is a galaxy-center planet with the coldest temperature of -220C; Kepler 22b is a super-Earth with a mega ocean; Kepler 78 b is a magma world
Highly recommend this beautiful book.
January 21, 2025
Probably one of the driest sci-comm reads I had in a while, but I still did learn stuff so obviously not a waste of time.
The book starts by describing the recent exploratory missions to find life outside of Earth. Firstly, by explaining the geochemical features of planets that we have reached and then by hypothesising those we have not. The book then changes tone and asks the reader to reflect on what even life is and that what we might find on other planets will likely not look the same as what we have on Earth. Carbon might not be the primary element of organic matter. Organisms might not primarily rely on Oxygen for energy production and so on. It then goes on to describe the SETI efforts to communicate with potential extraterrestrial forms and the likelihood of those even existing. My favourite part was maybe the Epilogue, where the author highlights the climate changes issues and how important it is for us to safeguard the only planet the - for now - we can inhabit.
The key issue with this book was that it did not - in my opinion - have a well defined audience. As a scientist, this book read like a less detailed literature review. Very few references to actual papers, while only generally talking abot the exploratory missions and studies. I was kind of hoping to learn more about the actual chemistry, biology and astrobiology techniques used in these studies - whilst those were only briefly brushed on. Meaning that the book resulted highly repetitive but not detailed enough. On the other hand this is not a sci-comm book for the general public. Again, the language is not catchy enough and - maybe most importantly- not simplified enough. Lots of things are taken for granted like names of chemical compounds and some physical terms like Doppler effects. Whilst it is things most of us study in high school - I don’t believe this is “common knowledge”.
Overall, whilst this was advertised as “astrobiology for all” is ended up being a book for few. Maybe a recap for those who want a refresh on topics they already know.
What I know for certain is that 22£ was definitely not worth it.
The book starts by describing the recent exploratory missions to find life outside of Earth. Firstly, by explaining the geochemical features of planets that we have reached and then by hypothesising those we have not. The book then changes tone and asks the reader to reflect on what even life is and that what we might find on other planets will likely not look the same as what we have on Earth. Carbon might not be the primary element of organic matter. Organisms might not primarily rely on Oxygen for energy production and so on. It then goes on to describe the SETI efforts to communicate with potential extraterrestrial forms and the likelihood of those even existing. My favourite part was maybe the Epilogue, where the author highlights the climate changes issues and how important it is for us to safeguard the only planet the - for now - we can inhabit.
The key issue with this book was that it did not - in my opinion - have a well defined audience. As a scientist, this book read like a less detailed literature review. Very few references to actual papers, while only generally talking abot the exploratory missions and studies. I was kind of hoping to learn more about the actual chemistry, biology and astrobiology techniques used in these studies - whilst those were only briefly brushed on. Meaning that the book resulted highly repetitive but not detailed enough. On the other hand this is not a sci-comm book for the general public. Again, the language is not catchy enough and - maybe most importantly- not simplified enough. Lots of things are taken for granted like names of chemical compounds and some physical terms like Doppler effects. Whilst it is things most of us study in high school - I don’t believe this is “common knowledge”.
Overall, whilst this was advertised as “astrobiology for all” is ended up being a book for few. Maybe a recap for those who want a refresh on topics they already know.
What I know for certain is that 22£ was definitely not worth it.
May 28, 2025
3.5 (at best) rounded down, just as I gave the broadly parallel, but more lacking, book by Phil Plait 2.5, rounded down.
The best part is discussing past, current and planned future missions by NASA, ESA, etc. to various planets, comets, etc., in our solar system. Second best was looking at the search for exoplanets to date.
Split decision at best on other things. Not much discussion of the current state of classical SETI, ie, looking for electromagnetic frequencies that might indicate intelligence "out there." Hat Creek is mentioned, but no mention of planned completion date. This ties in with a split decision on something else.
Cabrol says we may have a too-narrow view of life, but doesn't dive that much into alternatives like silicon-based "organics" etc. Nor does she touch on the possibility of intelligent life, whether due to its "seeing" and "hearing" senses being at far different frequencies than ours, broadcasting at far different frequencies than ours. I wrote about that years ago as part of a critique of the Drake equation. (Cabrol has a failure here in that while she [eventually!] actually presents the equation, she doesn't get into a detailed discussion of its different variables, any semi-consensus as to their current values, etc.)
And, while she does talk about the "Rare Earth" idea — that, even with all the exoplanets, and that many may be conducive to some form of life, few are conducive to intelligent life — she never ever mentions Steve Gould's famous thoughts on contingency and that if you rewound the tape and played it again, nothing would be the same.
Finally, I found the repeated references to Sagan a bit name-dropping.
The best part is discussing past, current and planned future missions by NASA, ESA, etc. to various planets, comets, etc., in our solar system. Second best was looking at the search for exoplanets to date.
Split decision at best on other things. Not much discussion of the current state of classical SETI, ie, looking for electromagnetic frequencies that might indicate intelligence "out there." Hat Creek is mentioned, but no mention of planned completion date. This ties in with a split decision on something else.
Cabrol says we may have a too-narrow view of life, but doesn't dive that much into alternatives like silicon-based "organics" etc. Nor does she touch on the possibility of intelligent life, whether due to its "seeing" and "hearing" senses being at far different frequencies than ours, broadcasting at far different frequencies than ours. I wrote about that years ago as part of a critique of the Drake equation. (Cabrol has a failure here in that while she [eventually!] actually presents the equation, she doesn't get into a detailed discussion of its different variables, any semi-consensus as to their current values, etc.)
And, while she does talk about the "Rare Earth" idea — that, even with all the exoplanets, and that many may be conducive to some form of life, few are conducive to intelligent life — she never ever mentions Steve Gould's famous thoughts on contingency and that if you rewound the tape and played it again, nothing would be the same.
Finally, I found the repeated references to Sagan a bit name-dropping.
May 23, 2025
Review of The Secret Life of the Universe by Nathalie A. Cabrol (with reflections on Henry Gee’s The Rise and Fall of the Human Empire
I had read Henry Gee’s The Rise and Fall of the Human Empire before starting The Secret Life of the Universe by Nathalie A. Cabrol. Gee frequently references Edward Gibbon’s classic The Decline and Fall of the Roman Empire to frame the fragility of civilisation. But while Gibbon hinted at the emotional and moral decay that contributed to Rome’s collapse, Gee stops short—missing what I believe is the deeper force at play:
Fear.
Not fear of extinction—but fear as a driver.
Fear as the hidden engine behind control, division, distraction, and disconnection.
The very fear that once helped us survive may now quietly undo us.
Gee’s conclusion is that humanity must look beyond Earth to survive.
That realisation flowed directly into Cabrol’s book—a very different kind of journey. While Gee offers space as a necessity, Cabrol explores it as possibility: the origins of life, the vast unknowns of the cosmos, and the questions that connect us as a species.
She writes with scientific depth, but also with humility and wonder.
And again, I kept circling back to one thought:
If we bring our fear with us into space, what exactly are we escaping?
Without emotional evolution, no technological leap will save us.
We may simply export our dysfunction into new worlds.
Gibbon saw the emotional erosion at the heart of Rome’s decline.
Gee maps out the fate of our species—but overlooks that same emotional core.
Cabrol offers a vision of what might lie beyond our world.
But between collapse and possibility lies the real challenge:
It’s not just the planet we need to leave behind—it’s the fear.
I had read Henry Gee’s The Rise and Fall of the Human Empire before starting The Secret Life of the Universe by Nathalie A. Cabrol. Gee frequently references Edward Gibbon’s classic The Decline and Fall of the Roman Empire to frame the fragility of civilisation. But while Gibbon hinted at the emotional and moral decay that contributed to Rome’s collapse, Gee stops short—missing what I believe is the deeper force at play:
Fear.
Not fear of extinction—but fear as a driver.
Fear as the hidden engine behind control, division, distraction, and disconnection.
The very fear that once helped us survive may now quietly undo us.
Gee’s conclusion is that humanity must look beyond Earth to survive.
That realisation flowed directly into Cabrol’s book—a very different kind of journey. While Gee offers space as a necessity, Cabrol explores it as possibility: the origins of life, the vast unknowns of the cosmos, and the questions that connect us as a species.
She writes with scientific depth, but also with humility and wonder.
And again, I kept circling back to one thought:
If we bring our fear with us into space, what exactly are we escaping?
Without emotional evolution, no technological leap will save us.
We may simply export our dysfunction into new worlds.
Gibbon saw the emotional erosion at the heart of Rome’s decline.
Gee maps out the fate of our species—but overlooks that same emotional core.
Cabrol offers a vision of what might lie beyond our world.
But between collapse and possibility lies the real challenge:
It’s not just the planet we need to leave behind—it’s the fear.
July 11, 2025
There's a tremendous amount of material of UFOs and space aliens so it's good to read a book that deals with whether or not there actually is life anywhere else in the universe and this book does a really good job examining that question.
Of course at the moment we have no proof of life of any kind existing anywhere else but on the Earth but the book examines how many other planets there are (and over 5000 of them are Earth-like in general), how life evolved on the Earth and changed over time, other places in our own solar system where some kind of life might have arisen and even still exist (and in the term life this means any kind of life, not just thinking beings. A lot of t could be micro-organsms of some kind that just remain that way and don't evolve.)
The topic of Earth-like (in general) planets is covered in detail along with the the physical requirements needed for particular planets to have life of any kind on them. (Be of useful size, don't be too close or too far away from the star they revolve around, etc.)
Then author goes into the Drake equation which tries to come up with a general number of inhabited planets in our galaxy which then leads into the Fermi paradox which is why, if there are so many planets with intelligent life on them, why haven't we detected any of them? (The UFOs might be driven by alien life or may be of some other kind of thing.)
The book also explores what they might look like.
Also important is that the book is written in a manner which is understandable even if the reader is not a expert on the topic themselves. Definitely worth reading.
Of course at the moment we have no proof of life of any kind existing anywhere else but on the Earth but the book examines how many other planets there are (and over 5000 of them are Earth-like in general), how life evolved on the Earth and changed over time, other places in our own solar system where some kind of life might have arisen and even still exist (and in the term life this means any kind of life, not just thinking beings. A lot of t could be micro-organsms of some kind that just remain that way and don't evolve.)
The topic of Earth-like (in general) planets is covered in detail along with the the physical requirements needed for particular planets to have life of any kind on them. (Be of useful size, don't be too close or too far away from the star they revolve around, etc.)
Then author goes into the Drake equation which tries to come up with a general number of inhabited planets in our galaxy which then leads into the Fermi paradox which is why, if there are so many planets with intelligent life on them, why haven't we detected any of them? (The UFOs might be driven by alien life or may be of some other kind of thing.)
The book also explores what they might look like.
Also important is that the book is written in a manner which is understandable even if the reader is not a expert on the topic themselves. Definitely worth reading.
September 18, 2025
Fascinating Book!
This wasn’t the easiest book for me to read because a lot of the science went way over my big dumb head. But the parts I did comprehend were fascinating. Astrobiologist Nathalie A. Cabrol does a wonderful job of taking the reader through our solar system and then onto the universe at large in a search, not just for life, but for planets and moons that are habitable. She and I share the belief that there has to be life somewhere out there. There are just too many exoplanets in what we call the habitable zone of sun-like stars (some estimates put that number in the hundreds of millions in just our galaxy alone) for the spark of life to have only happened once. Or, as she writes “thinking that we are alone in this cosmic ocean is simply a statistical absurdity.” But we had better hurry up if we are to find it, because as she points out, our Sun is growing in brightness and about a billion years from now earth will be inhabitable.
Besides the search for life, which also must begin with the definition of what life is, this book was filled with interesting tidbits. For example, I never knew a year on Venus is shorter than a day on Venus.
I enjoyed this book, even if I struggled to understand certain sections, and I know the next time I’m staring up into the nighttime sky I’ll feel differently about all those twinkling stars.
This wasn’t the easiest book for me to read because a lot of the science went way over my big dumb head. But the parts I did comprehend were fascinating. Astrobiologist Nathalie A. Cabrol does a wonderful job of taking the reader through our solar system and then onto the universe at large in a search, not just for life, but for planets and moons that are habitable. She and I share the belief that there has to be life somewhere out there. There are just too many exoplanets in what we call the habitable zone of sun-like stars (some estimates put that number in the hundreds of millions in just our galaxy alone) for the spark of life to have only happened once. Or, as she writes “thinking that we are alone in this cosmic ocean is simply a statistical absurdity.” But we had better hurry up if we are to find it, because as she points out, our Sun is growing in brightness and about a billion years from now earth will be inhabitable.
Besides the search for life, which also must begin with the definition of what life is, this book was filled with interesting tidbits. For example, I never knew a year on Venus is shorter than a day on Venus.
I enjoyed this book, even if I struggled to understand certain sections, and I know the next time I’m staring up into the nighttime sky I’ll feel differently about all those twinkling stars.
March 10, 2025
Astonishingly good except for the last 50 pages, which is only ok. The book does a really strong job explaining how we think about the possibility that a planet might be able to host life. It works through what we know about how life developed on earth and goes through our solar system before spinning to the rest of the galaxy. The parts about how the habitable zone of the Sun may have changed over time and what this looks like for Venus was really interesting. I’m sure some of this is obvious but I hadn’t really appreciated how the Earth’s plate tectonics means that the oldest rocks on the planet aren’t that old. Also the careful dance between not being too hot or cold and how these things work over time.
Like the best of these astrophysics books it breaks your brain to think about the timeframes involved and what that means for both you as the reader and humanity write large.
The last 50 pages aren’t bad per se. But they feel much weaker. They sort of dabble into a rumination on AI and what that represents in terms of life in ways that just feels far less interesting that the rest of the book. But the rest is absolutely worth reading.
Like the best of these astrophysics books it breaks your brain to think about the timeframes involved and what that means for both you as the reader and humanity write large.
The last 50 pages aren’t bad per se. But they feel much weaker. They sort of dabble into a rumination on AI and what that represents in terms of life in ways that just feels far less interesting that the rest of the book. But the rest is absolutely worth reading.
September 19, 2024
The Secret Life of the Universe by Nathalie A. Cabrol
Summary: The subtitle of 'an astrobiologist's search for the origins and frontiers of life" sums up this book really well. The Secret Life explores potential locations in the universe where habitable life may have existed or could currently exist, drawing on data gathered from space exploration missions and telescopes.
Cabrol, a Director for SETI (Search for Extraterrestrial Intelligence), is an excellent guide for this topic and it shows through the pages. I found the chapters discussing the moons most likely to harbor life particularly captivating. The information on Europa, Enceladus, and Titan was thorough yet easy to understand, leaving me with a sense of hope that there could indeed be potential for life in our own solar system.
The Secret Life of the Universe includes discussions on Artificial Intelligence, Exo-Planets and even climate issues in our own backyard. There's even a quick line on whether the petrifying potential of self-replicating xenobots made of frog cells qualify as life.
Summary: The subtitle of 'an astrobiologist's search for the origins and frontiers of life" sums up this book really well. The Secret Life explores potential locations in the universe where habitable life may have existed or could currently exist, drawing on data gathered from space exploration missions and telescopes.
Cabrol, a Director for SETI (Search for Extraterrestrial Intelligence), is an excellent guide for this topic and it shows through the pages. I found the chapters discussing the moons most likely to harbor life particularly captivating. The information on Europa, Enceladus, and Titan was thorough yet easy to understand, leaving me with a sense of hope that there could indeed be potential for life in our own solar system.
The Secret Life of the Universe includes discussions on Artificial Intelligence, Exo-Planets and even climate issues in our own backyard. There's even a quick line on whether the petrifying potential of self-replicating xenobots made of frog cells qualify as life.
January 1, 2025
Some parts of this book are fascinating, particularly how life might have started on earth and the building blocks needed for this to happen. The descriptions of the many space probes within the solar system are also of great interest. But the description of conditions needed to support life on all the planets in the solar system and their moons is just too long and repetitive.
The final section discusses where the human race is heading on earth given our trashing of the planet and the increasing reliance on digital technology. This to me is out of place in the book given its title and main theme and is little more than the subjective thoughts of the author without any real evidence or basis. Her theme here is that humanity must save itself at all costs. Perhaps we should accept that humanity is an insignificant little blip which will be around for a tiny fraction of time on an insignificant planet, and we will die out, just like millions of other species on earth, and that will be that.
The final section discusses where the human race is heading on earth given our trashing of the planet and the increasing reliance on digital technology. This to me is out of place in the book given its title and main theme and is little more than the subjective thoughts of the author without any real evidence or basis. Her theme here is that humanity must save itself at all costs. Perhaps we should accept that humanity is an insignificant little blip which will be around for a tiny fraction of time on an insignificant planet, and we will die out, just like millions of other species on earth, and that will be that.
June 29, 2025
The most interesting concept in this book is called The Drake Equation. This is the equation that specifies the factors in what makes up life on other planets. One of the factors is the number of stars in the sky. Stars are important because many of them have planets orbiting around them. Some planets like Pluto are unhabitable because it is too cold. Another factor in the Drake equation is the number of planets that have detectable biosignatures in them. Common biosignatures are water and carbon. Carbon is a source of energy and heat that can be found in rocks and vegetation. The search for intelligent life is another factor in the Drake equation. The author raises the question what defines life. The two factors that define life is a form of communication and the presence of nutrients and minerals like water and phosphorus. I am sure that astrobiology is more complicated than the information I provided here. If anything, The Secret Life of The Universe motivates me to learn more about astrobiology.
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