Readable and fascinating. I was mesmerized by the questions and answers this book poses about the potential for life on other planets. Very engaging.

And interesting and accessible read for non-scientists like me. Thank you #Netgalley and #StMartinsPress for the opportunity to review.

I found this book to be very interesting. I love learning about space and found this book really approachable by using comparisons that are easy to understand. The author does a great job of keeping the information understandable while keeping me, the reader curious. I even enjoyed the commentary about science fiction (books and movies).

A good read on the science of searching for proof of life on other plants. I enjoyed the science and it was written in a way that was easy to understand for someone not working in astronomy or a related field.

I really enjoyed this. It happened to pop up in my reading lineup at the same time I was watching "For All Mankind" and I felt like the information in "Alien Earths" really added to the experience of watching a show about space exploration and the possibility of building a civilization on other planets. The information presented was comprehensive but never felt dry. Definitely a welcoming and fun read.

I appreciate NetGalley and the publisher for access to a digital ARC. My honest review is my own opinion.

Alien Earths: Planet Hunting in the Cosmos by Lisa Kaltenegger
Adult Popular Science / 3 Stars / Pre-2024 Review Copy

Finally, I whizzed through my second book this year on exoplanets, can you tell they're a favourite subject of mine? This fun book didn't really cover much new ground for me, but it was bang up to date with the latest research, and I always love to read anything I can about the hunt for planets outside our solar system and the new techniques being developed to find them. This is definitely a book I'd recommend to anyone interested in the subject, as it's light-hearted and easy to read while being packed full of information.

Thanks to NetGalley for the ARC of this book. I loved this science-y exploration of if life exists on other planets, and if so, how we'd be able to identify it. As a layperson, even though the author used a lot of analogies, there were parts that went over my head. That said, it was incredibly well-written, and though the author was humble, you can tell she's an absolute superstar scientist. It felt like an honor to learn from her.

I love learning about space. It’s so fascinating: there’s so much out there. I’d be beyond thrilled if I could just go up in orbit for an hour and see our beautiful home planet from above and get a better look at the stars from a different vantage point. So I appreciate nonfiction that gives me more insight into space, and I generally enjoy fiction set in space. Given that, I couldn’t resist picking up this nonfiction book about scientists looking for other planets that could host life.

The author of Alien Earths is an astrophysicist who is the founding director of Cornell University’s Carl Sagan Institute. She shares some of her background and talks about the many things that piqued her interest in space and the search for other planets. Kaltenegger’s interests and accomplishments certainly indicate she is a brilliant and curious woman.

It’s interesting to read about the various facets of science that she researches and the types of other scientists with whom she collaborates. For instance, readers may not think about how much biology comes into play in her field. But if you think a bit longer about it, it does seem a bit obvious that it must, since if we’re looking for signs of life on other worlds, we need to define (and study) life on our own planet!

Kaltenegger explains how scientists find stars and planets circling them, even though they’re many, many light-years away. Quick hint at one way they do that: look for wobbles.

She also talks about how even if we are able to see signs of possible life on planets far, far away — or if aliens were to see signs of life here — it would be signs of life from (likely) hundreds or thousands of years ago because of the light-year distances that will (again, likely) be involved. I have to say that when Kaltenegger explored that idea a bit toward the end of the book, it took me on a fascinating train of thought. Because of those extreme distances and the speed of light, we have to think differently about time and space. Rather than thinking about “now,” we have to think about past or future. I’m simplifying these ideas quite a bit here for all kinds of reasons, but suffice it to say it is a touch mind-bending.

I appreciated much of what Kaltenegger wrote about in Alien Earths, but I wasn’t glued to it, to be honest. I felt it was dry at times, though she was trying to inject a lot of personality and personal experiences into it throughout. While I do love science and books written for the general public on scientific subjects aren’t difficult for me to follow, this book still felt a bit too textbook-ish sometimes. I had to read it in smaller bites in between some other books to get through it. I can’t say that will be the case for other scientifically minded readers, however.

This was an interesting nonfiction book that discussed the search for life in our galaxy.
I enjoyed this book as some of the information provided was new to me. The book was interesting but I would suggest that it is written for an audience that is already interested in these topics. The author wasn't afraid to dive into some basic science and assume the reader is educated on the foundations of these topics.This was a fairly small book that felt just right for the topic discussed. I would recommend this to readers who like to learn through their reading time.

Alien Earths: The New Science of Planet Hunting in the Cosmos, by Lisa Kaltenegger is at times a fascinating book, is at times an inspiring book, is often an informative book, but also, unfortunately, is often a frustrating book. Or at least it was for me. It’s a worthy read, but one that feels like it could have been much more.

Kaltenegger is director of the Carl Sagan Institute to Search for Life in the Cosmos at Cornell University and as such is one of the best candidates for writing a book on exoplanets (those planets outside our own solar system), especially as her career has spanned the entire existence of exoplanets themselves (well, our awareness of their existence, they’ve existed for billions of years, and I’m pretty sure Kaltenegger is not that old). The details of that career, or at least some of them, are interwoven throughout the book, adding a welcome personal touch amidst the more removed science.

Kaltenegger opens by setting the stage for why we need to know more about exoplanets and why some think their existence makes the case for life beyond ourselves in the universe. Basically, it’s a numbers game, as she points out that “since the first extrasolar planets was discovered in 1995, astronomers have found more than five thousand others . . . One new world discovered for ever day sine we built the first instruments sensitive enough to detect them.” She goes to note that we’ve learned that planets are shockingly common, and given that the Milky Way has about 200 billion stars, we’re talking about (in true Sagan-speak) “billions and billons of new worlds to explore in our galaxy alone. Multiply by that by the number of galaxies (and our is hardly the largest), and, well, the point is self-evident.

From the introduction, the book moves on to various sections detailing the search for both exoplanets and life, exploring topics such as the various methods of detecting exoplanets, the telescopes and probes involved in the process both in the past and (hopefully) the future, the ways in which we might try to detect signs of life (which necessitates the surprisingly difficult task of defining life) from so far away, how we might use Earth and its signs of life as a guide, the possibility of communicating with other life if it exists, and more.

The science is all explaining quite clearly with mostly a lack of technical jargon and any that is required is just as clearly explained. If anything, I’d say the book is simpler than most popular science books I’ve read on this topic or similarly difficult ones (such as physics or biology). More than once, I found myself a little surprised at the choice to stop and explain what I would consider a relatively basic concept. That’s not a complain, merely an observation, one based I’m sure more on my frequent reading of popular science books/magazines than on any “dumbing down” by the author.

Her descriptions of specific exoplanets we’ve already learned some details about, meanwhile, often border on the lyrical and are wonderfully vivid and compelling as she describes a water world (with reference to the famous/notorious Costner film), or one that rains lava or other equally exotic ones. I actually found myself wishing both she had spent more time giving us more full descriptions of those particular planets and gave us more total descriptions of other one as well.

Similarly, I felt the same way about the more personal stories she offered up, such as the nerve-wracking experience of watching one of your projects being launched (fingers crossed) into space, and then the the several hundred steps she had to wait patiently through, knowing failure at any one would doom the mission. Or, on a less positive note, the experiences she had in facing sexism, ranging from an early school person telling her girls don’t really do very well in the math/science area or a pair of colleagues discussing how she only achieved the position she held at the time because she was a woman. We get these sorts of vignettes sprinkled throughout, but I would have been happy to have had the book balanced more equally between the science and the personal (and really, it’s hard to separate the two), more of a 50-50 split. That’s one reason I felt the book didn’t reach its full potential.

The other is that overall, it felt somewhat disjointed, a bit scattered and at times a bit too much like it was skimming the surface of things. It’s not that the personal touches interrupted things—those elements actually were almost always seamlessly integrated. It was in the organization of explanations and the movement from one concept or mission to the other. In fact, by the end of the book I had started to wonder if the book was actually based on a series of columns she had written and then strung together in more narrative form. It isn’t, but the fact I wondered about that gives you a sense of how disjointed it felt to me. It’s also probably true that the book suffered somewhat from my having read two similar books, each of which was quite strong (The Sirens of Mars: Searching for Life on Another World by Sarah Stewart Johnson and The Possibility of Life: Science, Imagination, and Our Quest for Kinship in the Cosmos by Jaime Green) and both of which appeared on my Best of the Year lists for their respective publication years.

I’m certainly glad I read Alien Earths, particularly for the lively descriptions of those dozen exoplanets, but I couldn’t help feeling tantalized by what the book could have been. Recommended with caveats.

There was so much to ponder in this book. I enjoyed this exploration of space snd planets, specially the look into what could sustain life. I found the book very readable and interesting.

In Alien Earths, Dr. Lisa Kaltenegger introduces readers to a broad overview of planetary science, beginning with our own solar system and quest to explore the cosmos, branching out into our search for Exoplanets.

Dr. Kaltenegger is the director and founder of the Carl Sagan Institute for the Search for Life in the Cosmos at Cornell. It is easy to see the inspiration of Sagan in this work, for better and worse. Dr. Kaltenegger is positioning this book to be for the average reader, an introduction to modern space science with hints of her own work. As an introduction, I think this would work for any interested reader, especially those who have an (illogical) aversion to older works. This book presents the most up-to-date science in a manner that is digestible and crafted to inspire. If you are that kind of reader, with no past exposure to the subject but still an interest to learn, this book is perfect for you. For everyone else, it is harder to recommend.

I am a planetary scientist and an astrobiologist. My focus is on surface evolution of planets and moons in the solar system. I am not an expert in Exoplanets, and I picked this up hoping for a deeper dive into that field. With that said, I can look at this book through both lens: as a reader eager to learn new things versus as an expert learning and/or judging how we can discuss the science we do. I was very disappointed as the learner and still mixed as the expert.

At least half the book or more is a very broad introduction to space and planetary science. I felt like this was done well, but I also think the lay reader could have been given a bit more trust to handle a deeper dive (the book is fairly short after all). My biggest issue with the introduction is that it felt like it didn't significantly reframe the conversation. Many of the analogies and philosophical musings were things I'd heard before. They are effective, but if I was going to recommend a book (or books) on this subject, I would still urge readers to try older works (e.g., Pale Blue Dot). Sure, science evolves and changes, but its more likely that what's changed is the clarity of what we know, like putting on glasses to refine what was already there.

Unfortunately, my disappointment extends beyond the introduction. Even as we venture into the realm of Exoplanets, there remains a vaguery on the subject. I say the introduction is long, but I am not exactly sure it was all an introduction. It wasn't clear that there was a lot of new science to be introduced. It is indicative of the larger style of only dipping the readers toes in anything being discussed. This is where I had my most personal disappointment. I expected this to focus more on exoplanets. We get to hear about her work and the ongoing efforts, but we never really get to immerse ourselves within it.

I recognize I come to this with biased perspective. I am not an exoplanet scientist, but I have a professional familiarity with the science as an astrobiologist especially. Still, it is that familiarity that makes this feel so underwhelming. I felt like I learned more from Dr. Sara Seager's book from nearly 5 years ago now, The Smallest Lights in the Universe: A Memoir. That's more a memoir than a science book. If I was going to recommend a book on exoplanet science, that would easily be it. The conversation on exoplanets is secondary, so it is unlikely to overwhelm the reader. It is also a very personal story. It is Dr. Seager's personal story with grief, as a scientist, and as a woman.

Overall, I can easily recommend this to anyone curious to explore the subject for the first time. I still think it fails to really excel, and the recommendation is largely on its recency being more likely to attract new interest in the field, which I am all for. However, that relevancy will fade, and I'll be surprised if became a classic in the field of popular space science books.

3.5/5 stars

Alien Earths by Lisa Kaltenegger is an exploration to discover other planets in our atmosphere. She is a lead astronomer at the Carl Sagen Institute at Cornell.
As someone who is a lay person when it comes to astronomy, she makes it easy to understand. She gives an in depth exploration of Earths history and other planets.

She introduces us to exoplanets and bridges the gap between science fiction and reality. She makes us ponder are we truly alone in this world?

Normally I don’t read to many books like this one but Dr. Lisa Kaltenegger wrote this complex science topics in a way that made it easy to understand.
It’s interesting to learn how scientists go about researching the conditions of life on our planet and what they are looking for on their plants. If you like to learn about our plant and other you’ll find this a interesting book to read

Alien Earths explores the science behind the search for life on other planets. This was a fascinating read and I loved how it was written. This is very beginner friendly and a solid foundation of astronomy isn't required to understand the topics. Dr. Kaltenegger uses simple descriptions and analogies, and breaks down the scientific explanations very well, as if I was in her class and also engaged in the discussion.

Each chapter, while lengthy, is broken down by subchapters exploring the various factors used in the search - such as, what exactly is life? While I have always loved astronomy and am not a beginner to the subject, I learned a lot from this. It made me think more about how we define life, the conditions necessary for life, and all of the scientific processes that are explored when considering what alien planets could hold life.

While this book is more of a summary on the science behind planet hunting, I really enjoyed that she approached all topics based on facts and not hypothetical topics. She breaks down the search for alien Earths by reflecting on what we already know about the universe, our solar system, and Earth - and how we use this information to look for habitable planets. I was never bored; each topic was fascinating and I loved her sense of humor.

4.5 stars - Dr. Kaltenegger's contributions to the field are awe inspiring and I would love to read more from her. Thank you to NetGalley and St. Martin's Press for a copy of the ARC in exchange for an honest review.

“So yes, Luke Skywalker could have enjoyed a warm day under two suns—but I always wondered where his second shadow was.”

Looking for potentially habitable planets has different meanings to different people. It can be a way to satisfy intellectual curiosity, or desire to find other life so that we know we are not alone, or a way to spread humanity across the universe (whether the universe needs it or not remains quite debatable), or a way for us to have a Plan B in case our wonderful and perfectly suited for life as we know it Plan A of Planet Earth becomes less human life-friendly. Whatever is the reason, the search for potentially habitable exoplanets quickly went from the realm of science fiction to the realm of science.

And the potential for habitable planets is quite impressive. They seem to be pretty much everywhere, apparently. And Lisa Kaltenegger is beyond excited about them.

“We have no photo of the two hundred billion stars in our Milky Way—and we won’t have one for a long while. To fit the entire Milky Way in a photo, a spacecraft must fly far away from Earth, and far above the plane of our spiral galaxy. And no spacecraft has even made it to the next star over yet. The Earth is like a piece of pepperoni on a pizza trying to imagine the whole pizza’s shape. One of the main differences between us and the questioning pepperoni is that we have figured out what our galaxy looks like.”

It’s a very accessible read that can serve as an easy primer on a fascinating subject. Kaltenegger - despite the serious title of the director of Cornell University's Carl Sagan Institute - keeps it simple and clear, with the end result of it being interesting and comprehensible to pretty much anyone with zero science background. Not to mention extra nerd points for referencing a few science fiction books and films (I like Andy Weir too, Lisa!). It’s a great book to get people interested in the topic without getting bogged down too much in hard science behind it.

3.5 stars that I’m happy to round up.
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Thanks to NetGalley and St. Martin’s Press for providing me with a digital ARC in exchange for an honest review.

I find the study of space and possibility of other life out there to be fascinating. The problem with many of the books on the subject out there is that they are often either dry or so technical as to be off-putting to most readers. I’m delighted to say that is most definitely not the case with Lisa Kaltenegger’s Alien Earths: The New Science of Planet Hunting in the Cosmos. She pulled me in right from the start and when she started talking about the discussions and how she approaches things in her class it made me wish I could sit in on some of lectures. (I did find that she is featured in a number of videos on Youtube and I’m currently making my way through those.) Does she answer the question of are we alone in the universe? Well not definitively. No one really knows just yet. Now I’m not even going to attempt to give a full run down of all the information she imparts, but what she does discuss is explore the why of why we might not have made contact yet and the how scientists are going about trying to discover that answer. This is an informative and easily accessible book for anyone interested in the subject of are we alone in the universe. I’d like to thank St. Martin's Press and NetGalley for the opportunity to read and review an eARC of Alien Earths.

https://www.amazon.com/review/RLIBIRF5JX2O1/ref=pe_1098610_137716200_cm_rv_eml_rv0_rv

What kind of plan would you make if you wanted to look for life beyond Earth? Lisa Kaltenegger is one of the people who have done just that and she shares the hows and whys in this very readable book. So where does one begin? The whole process is one of narrowing the fields. Agree to a definition of ‘life’ then decide what is necessary to sustain such life. Then start looking. We all know it’s not that easy and one of the beauties of this book is that Kaltenegger explains complicated ideas and actions in an easy to follow manner. She tells how exoplanets are found and what it’s possible to learn about them. And there is the surprise of worlds that seem impossible. The story is ongoing with anticipation of what new tools, new telescopes, new theories will bring.

Alien Earths is one of those thought-provoking books that I have found myself unable to stop talking about with friends and family. I have long been fascinated by the idea of life outside of our solar system and was aware of research endeavors such as SETI, however I had no idea of the strides the scientific community has taken to search for life without signal intelligence. The more I read about the use of telescopes to detect the chemical compositions of planets along with color and light spectrum, the more interested I became. Dr. Kalteneggar does a phenomenal job of explaining the science in both technical and laymans terms. Her writing is well organized, concise, and full of current and exciting research. I only wish that there were illustrations included to help better visualize things such as binary star systems or to illustrate exactly where the Goldilocks zone might be in different star types.

I highly recommend this book for all the space nerds out there or anyone who is interested in current research into life on other planets.

Thank you to NetGalley, Dr. Lisa Kaltenegger, and St. Martin's Press for an advanced reader's copy in exchange for an honest review.

Thank you St. Martin’s Press, Macmillan Audio & Netgalley for sending me an ARC in exchange for an honest review! I wasn’t sure if I was going to like this book or not because when I was in school, I thought Science was boring. I don’t know anything about Science or Space but I enjoyed reading this book. This book never felt dry or boring. This book is very readable. I learned so much and it has made me interested in Science. I would recommend this book if you don’t know anything about Science or Space.