The Planet Factory: Exoplanets and the Search for a Second Earth

by Elizabeth Tasker

Twenty years ago, the search for planets--and life--outside the solar system was a job restricted to science fiction writers. It is now one of the most rapidly growing fields in astronomy, with thousands of these "exoplanets" discovered so far. The detection of these worlds has only been possible in the last decade, with the number of discoveries increasing enormously over the last year following the findings of the Kepler Space Telescope.

These new worlds are more alien than anything in fiction. Planets larger than Jupiter with years lasting one week, planets circling the dead remains of stars, others with two suns lighting their skies or with no sun at all. These locations hint at Earth-sized worlds but with split hemispheres of perpetual day and night, waterworlds drowning under global oceans, and volcanic lava planets spewing seas of magma.

The Planet Factory tells the story of exoplanets, planets orbiting stars outside of our solar system. Discover the specks of dust that circle a young star come together in a violent building project that can form colossal worlds hundreds of times the size of the Earth; the changing orbits of young planets that risk dooming the life forming on neighboring worlds or, alternatively, that can deliver the key ingredients needed to seed its beginnings. Exoplanets are one of the greatest construction schemes in the universe and they occur around nearly every star you see. Each result is an alien landscape, but is it possible that one of these could be like our own home? The Planet Factory discusses the way these planets form, their structure and features, and describes in detail the detection techniques used (there are many) before looking at what we can learn about the surface environments and planetary atmospheres, and whether this hints at the tantalizing possibility of life.

An informative and entertaining read, The Planet Factory takes the reader to the cutting edge of the ongoing search for worlds like our own, and the hints of life elsewhere in the cosmos.

Genres: Science, Nonfiction, Space, Astronomy, Physics, Popular Science, Planetary Science

352 pages, Paperback

First published September 7, 2017

About the author

Elizabeth Tasker is an astrophysicist and science communicator working at the Japan Aerospace Exploration Agency (JAXA) in Tokyo.

Her research explores how stars and planets form by building mini universes inside her computer. She is a keen blogger, feeling that there is an equally great story in a trip across the world as there is in making use of a public bathroom. This ideology was confirmed when she won the 'Leap Local' travel writing awards in 2010 for an article on Japanese toilets.

Her popular science book, 'The Planet Factory', was published in September 2017 (November 2017 in the USA) by Bloomsbury Sigma. Her science writing has also appeared in Scientific American, Astronomy Magazine, NExSS Many Worlds, Nautilus, space.com and the Conversation.

Elizabeth lives in the Tokyo area with her cat, Norah. Her personal blog and a selection of her writing can be found at http://girlandkat.com, while her professional work page is at http://elizabethtasker.com .

Reviews

[Rachel (Kalanadi) · Rating 4 out of 5]

This is THE book on planet formation and the search for exoplanets.

I loved the focus on process and formation. Tasker demonstrates over and over again how our assumptions and theories about planets, solar systems, and what's possible out there get overturned all the time by new discoveries and new data. A hypothetical formation process is suggested to cover the size and orbit of one exoplanet, then needs to be revised again and again as new "formerly impossible" exoplanets are discovered.

And this calls into question our own solar system - are WE the weird ones? Are we rare? Do we need to disregard all our assumptions about planets and life when we search farther and farther out?

Tasker lets her audience have ALL the information about planets. This is some pretty technical stuff and Tasker doesn't skimp. I assume she's left out the very, VERY technical stuff, for accessibility reasons, but this is not a dumbed down version with all the corners rounded off. Some parts read a little like a textbook, but it was always interesting and the occasional side remark in the footnotes added personality.

Unlike other pieces I've read on exoplanets, The Planet Factory always seemed firmly rooted in what we know (and what little we sometimes can find out), rather than speculating too much and creating an "artist's impression" instead of a scientific one. I'm going to be rather put out next time I read a sensationalistic news article touting "the most Earth-like exoplanet yet", because the real scientific data probably doesn't support that (it will be real news when it does!).

Highly recommended for readers and amateur scientists searching for detailed and cutting edge information on planetary science and exoplanets.

(My understanding is that The Planet Factory is out in the UK now, and will be out in the US in November 2017. I received an e-ARC from NetGalley for review, so thank you to NetGalley and the publisher.)

[Brian Clegg · Rating 3 out of 5]

The way this book opens has the feel of an author trying too hard to get her personality across, as popular science books sometimes do. Elizabeth Tasker opens by asking an astrophysicist 'What would make you throw my book out of the window?' and as a reader, I hardly take in the next page and a half wondering why anyone would ask such a question. Then, just as I regain the ability to process what I'm reading, I get 'In 1968, Michael Mayor fell down an ice crevice and almost missed discovering the first planet orbiting another sun'. And I'm thinking 'But no one made such a discovery in 1968', not realising that this statement had nothing to do with his much later work on exoplanets (planets that orbit other stars) but was just a way to try to make the character more interesting.

Thankfully, once we get past the introductory section, Elizabeth Tasker's style settles down in a big way - if anything it goes to the other extreme and becomes distinctly dry, delivering more of a collection of facts than a narrative. However, in terms of content, The Planet Factory can't be faulted. It is excellent, for example, on planetary system formation. We're used to hand waving explanations of planetary formation from a disc of dust and gas, but Tasker shows how there's not long (in planetary timescales) for this to happen, and why it's really distinctly difficult for a cloud of dust grains to do anything more than bounce off each other, rather than clump together to form a planet.

Even in the heavy fact sections there is a tendency to use odd analogies, for example: 'this uncertainty leaves us as much in the dark about the planet's type as would the sex of a foetus with its legs crossed in the womb,' but these become less frequent after a while. Tasker gives us oodles of detail, emphasising how complex the planet formation process is, as new discoveries often make old theories wrong, or at least throw oddities into the mix. As readers, we soon realise that an awful lot is being deduced from a relatively tiny amount of data, so there is a strong whiff of speculation in the air much of the time. This is emphasised when Tasker describes the way that three planets found orbiting Gliese 581 were later thought not to exist - in the case of two of them, it was enough that the star had the equivalent of a strong sunspot to produce the misleading data.

This is the first popular book I've read about the formation of both our solar system and exoplanets that gives a real, gritty, coal-face feel for the complexity of the process involved, how much we know... and how much we don't. To be honest, it's not the most engaging book - I don't think that's Tasker's fault - it's just that as a topic it's rather like geology - probably the hardest of all scientific topics to make interesting to the general reader. It's notable that in the final section, where Tasker takes on whether or not planets (and moons) are correctly placed to be able to provide the essentials for life as we know it, things get more interesting. But if you have an interest in the solar system or planetary formation on a wider scale, and are hazy on the details, it's a must-read.

[Ajith Ashokkumar (LordOfBooks) · Rating 4 out of 5]

In this wonderful book the author introduces us how the Planets and its satellites are formed and the whereabouts of the exoplanets discovered so far. We identified planets like Kepler 186f which are at an enormous distance of 500 light years away from our earth.
When we started our voyage towards space, we were successful only reaching the moon. Moon is just 1.25 light seconds away from earth, i.e; 0.00000004 light-year distance, it would take approximately 3 to 7 days to reach the moon. So to our nearest exoplanet, how long would it take to visit Proxima Centauri-b? Its 4 light years away from earth, 4 light years sounds tiny compared with the 500 light-year distance of Kepler-186f. Our farthest and fastest travelling spacecraft is Voyager 1, which would still take 75,000 years to reach Proxima Centauri if it were orientated in the right direction.
Scary right?!. This signifies how smaller the humans are compared with the vastness of this universe.

[Nicky · Rating 3 out of 5]

Reviewed for The Bibliophibian.

If you’re interested in planets outside our solar system, this is obviously going to be for you. It explains how planets form and the different ecosystems (of a sort) that different types of planets form in. Like the other Bloomsbury Sigma books, it’s readable and fairly light in tone. I think it could actually have used some more diagrams: sometimes, Tasker explained something and my brain just couldn’t grab hold because I couldn’t do the imagining she was suggesting. (If you start with “imagine an ellipse”, I’m afraid I fall at that first hurdle, so I’m a bit of an outlier here — but I still think some more diagrams could have clarified the more technical stuff.)

I do also have some issues with terminology, although this isn’t Tasker’s fault so much as an issue with astronomy in general: hot Jupiters and super Earths and so on all start to blur together for me. Once you say “it’s like Jupiter only x and y and z and a and b” then I don’t know why you’re still calling it a Jupiter-like object. Some of the hot Jupiters are pretty close to Jupiter, of course, but… I don’t know, it felt like a meaningless phrase that got in the way of me actually following what sort of planets were being discussed. “A gas giant on a close solar orbit” seems more informative…

Anyway, that’s probably mostly down to personal taste. It’s an informative book with which I have no scientific quibbles.

[John B. · Rating 4 out of 5]

3.5 Stars rounded up. I enjoyed the author's writing style on a complex subject. Reading this increased my interest in planetary science and astrophysics. Many times this felt like a one-on-one tour through the papers presented at a planetary science conference. The reader is presented with observational data and how the experts in the field interpret their findings. Detail is added on how the interpretation is supported (or not) by simulations and theory. Setting up and exploring the theory and simulations for a reader not skilled in the art does take some effort and patience to work through, but the reader's efforts and patience are fully rewarded. Once the reader is placed on a firm foundation as to what experts think we know and why we think we know it, the argument is carried one step further by looking at, what I will call, "variations on a theme". Perhaps those in the field would simply say "thinking like a planetologist".

Modern astronomy is the beneficiary of a treasure trove of observations. The author explains in detail how theory and simulations help us understand the observations, and then she pulls back the curtain and reveals the moving levers behind the simulation and theory. What if the planet was in a closer orbit to the star? What if the frozen ocean were thicker? In the process of exploring and varying the experimental parameters of the theory and simulation the reader is enriched with a greater understanding of the many varieties of planets and solar systems that have been discovered. This "what if" discussion based on the simulation results (and no doubt published in greater detail in a journal or conference paper) was a pleasure to read. In many ways the book reads as if I had the opportunity to sit down for lunch everyday with an astrophysicist and have them take the time to explain their work: what they are doing, what they enjoy, what they are learning, and what it leads to. I typically don't enjoy reading popular science books because they are heavy on jargon and very light on knowledge and understanding. This book limits jargon and invests in educating the reader on the foundations of planetary science as it is understood at the end of the second decade of the 21st century.

As a reader of science fiction this book has made me aware of the many possibilities for alien worlds. Too many times science fiction has provided stories on alien worlds that are impossible. The reality of what can exist is more complicated and mind-blowing than the most enthusiastic science fiction author can manufacture. I would encourage aspiring authors to read this book before crafting their story about a desert world or jungle moon. There are multiple reference to Star Wars worlds and solar systems. One imagines that seeing the binary suns on Tatooine through the eyes of Luke Skywalker has launched more than one aspiring scientist on to a lifetime of learning the science behind the creation of the universe. In one of the "what if" discussions the question is asked "could any liquid water truly exist on a world with a circumbinary P-type orbit around two stars?" (p. 265) This is directly relevant to understanding the climate possibilities on Tatooine. After an interesting discussion educating the reader on temperate zones around binary stars, the author offers this side note to those wanting to know "film footage of the twin stars in the sky about Tatooine suggests that the temperate zone would be very lopsided." Thinking like a planetologist will not only enrich your subsequent viewing of Star Wars, it will increase your appreciation for the world we call home.

Elizabeth Tasker has an excellent writing style and I look forward to reading her next book.

[Alexander Páez · Rating 4 out of 5]

Ameno, divertido y fácil de entender. Una cosa que me ha gustado especialmente es que puedes aparcar el libro y volver y retomas fácil el hilo debido a la estructura propia del mismo. Algo que he agradecido para intercalar con otras lecturas.

[Pop Bop · Rating 4 out of 5]

How To Build A Planet, or To Find One That's Already Been Built

You know how with many college science courses they number them from intro courses up to pre-major? So you get Bio 101, Bio 103, Bio 105, and Bio 107, and then you select more advanced courses in the major. Well, I'd put this text somewhere between Astrophysics 105 and Astrophysics 107. An interested amateur can get most of it, (or all of it if he really, really tries), but there is no shame in browsing/skipping a bit here or there.

The book is fairly described by the blurbs that promise it will "demystify the crucial technical details of the research with impressive clarity and a light, engaging touch". The important point is that the material is indeed presented clearly, the author does have a light but not overly jokey or dummified touch, and there are a lot of technical details. And once you realize that there will be no final exam you can relax and enjoy the ride.

I did start this book with the mistaken expectation that it would mostly be a tour of the different possible types of exoplanets, along the lines of those books of speculative art that imagine what the landscapes of other worlds might look like. There's some of that, but just some. This is a more technical and rigorous work that focuses heavily on how tiny bits of dust in the planetary disc around a new star can ever grow to be a planet. We start with how exoplanets are found, (radial velocity technique, transit technique, and so on), but this book is primarily about how planets are made - how they make themselves and how they make each other, why they are composed of certain elements, and why they are where they are instead of somewhere else.

To get into the material we start with out own solar system and a discussion of how each of the planets we are familiar with might have come to be. We consider the other types of planets that we don't have, but that could exist. We then review how exoplanets are found. We talk about what we know is out there, and then we talk about what might be further out and how we might go about looking for them. In the course of doing all of that we have to consider all of the different types of stars and star systems, and how each might have its own sorts of planets.

There's a sort of chicken and egg problem here. Do you find something and then try to figure out what it is? Do you posit what might exist, and then try to find it? Do you find something and then work backwards to recreate how it came to be? Do you theorize a planet making process, and then look for a planet that may have been made that way? Our author does all of that, sometimes at the same time. If this book has a challenge it would be how to organize, make sense of, and present the field. This isn't settled material, and it hasn't developed in a nice straight line. All of this science is happening right now; ideas and discoveries are popping up all over, and every direction you look something is happening. Tasker does a wonderful job of trying to keep the story, (the problems, the solutions, and the problems with the solutions), on track, but sometimes she's herding Schrodinger's cats.

There are also fascinating digressions. I very much enjoyed the discussion of how you look for markers that suggest life on various exoplanets. There is a good deal of discussion of Pluto, (not just griping about its demotion), that explains why Pluto is different, and this segues into a discussion of a possible Planet 9 and of other planetary objects that orbit our sun, (who knew about Sedna?, or that Neptune was so important).

The bottom line is that if you are at all interested in planetary science or astrophysics, this book is a rich and rewarding feast. A very nice find. (Please note that I received a free advance ecopy of this book without a review requirement, or any influence regarding review content should I choose to post a review. Apart from that I have no connection at all to either the author or the publisher of this book.)

[Peter Tillman · Rating 3 out of 5]

A good, up-to-date summary of the search for and discovery of exoplanets, planets around other stars. This is pretty much essential reading for people who are interested in this search, which certainly includes me.

Things that struck me while reading the book:
* The discovery of exoplanets is really, really hard, finicky work.
* Astronomers were always pretty sure that other stars had planets. And they assumed other solar systems would be pretty much like ours. This wasn't the case!
* The easiest exoplanets to find are large, and orbit near there parent stars. But it was still a big shock to find so many "hot Jupiters"!
* Per Sara Seagar, a noted planet-hunter:
"Any planet you can imagine is probably out there, somewhere, as long as it fits within the laws of physics and chemistry."
* There are a lot of planets out there. Billions and billions of them! And the techniques and technology for finding them are still getting better. Early days in this branch of astronomy.

So, why only three stars? The author is not a graceful writer, and that's being kind. Be prepared for all sorts of jarring phrases and similes. And the proofreading is pretty bad. I still recommend the book, but I wish it had been better-written, and more carefully edited. You should still read it. I've followed the search pretty closely, over the years, and I still learned a lot.

[Rbjumbob · Rating 5 out of 5]

Ms Tasker styles a wonderful breath of fresh air. This is far from science textbook. It’s more like sitting down and having a conversation with a really knowledgeable friend. I appreciate all the effort she put into putting this book together lotta research all the references are there job well done.

[lauren chapple · Rating 4 out of 5]

this book made me feel like a woman in stem

[Ben · Rating 4 out of 5]

This is an excellent survey of exoplanet science, for a general audience.

My main complaint is that Tasker too often tells a story, e.g., of exoplanet formation, without telling us how we know that story or what the uncertainties are. The process of science is as important as the conclusions, and Tasker sometimes shortchanges us. Not always, though—I just wanted more details. Although the book is very well organized, I would have liked to learn more of Tasker's own (presumably more specialized) research. Her webpage says, "My research uses computer models to explore the formation of planets and galaxies," but this doesn't come out at all in the book. There is some description of the techniques for discovering exoplanets, but nothing on computer modeling.

More typos than I like ("numeracy," incorrect Celsius/Fahrenheit conversions, …).

> Should the estimated location of the Solar System's centre of mass be wrong, the true distance between the Earth and pulsar will be slightly off and the pulsar timings will appear irregular. In 2005, the arrival times of pulsar signals were scrutinised for evidence of an anomalous variation that would indicate a missing planet. They came up blank

> Modelling virtual systems that begin with five gas giants turns out to be more successful at reproducing our own Solar System than with just the big four. The extra planet forms just past Saturn with a similar size to the two icy worlds, Uranus and Neptune. During the ensuing chaos of planet rearrangement, this extra world passes slightly too close to Jupiter, which aggressively boots it from the Solar System.

> Although the carbon-silicate thermostat allows the Earth to compensate for small changes in the Sun's radiation, there is a limit. If the Earth is pushed too close to the Sun, the increase in water vapor cannot be compensated for swiftly enough by the reduction in carbon dioxide. The planet therefore heats still further and more water is evaporated into the atmosphere to boost the greenhouse effect. As temperatures pass 100°C (212°F), it stops raining and carbon dioxide removal is throttled. The greenhouse gases continue to climb through water evaporation and volcanic activity, raising the temperature continuously higher. Carbon is baked out of the rocks to escape into the air and react with oxygen to add still more carbon dioxide to the atmosphere. A runaway cycle ensues whereby the planet continues to get hotter and hotter until all the water is gone from the surface. This is probably the fate Venus met.

> This fails once the temperature drops sufficiently for the carbon dioxide to condense into clouds. Clouds of carbon dioxide reflect and block more of the Sun's diminishing heat to boost, rather than counter, the planet's cooling. The surface temperature on a more distant Earth would drop to zero at 1.4–1.7au. This is the point known as the Maximum Greenhouse limit

> In our Solar System, the temperate zone extends from 0.95au to 0.14au for a conservative estimate, and 0.84au to 1.7au at the generous edge.

> the temperate zone is planet dependent. Boost the Earth's carbon dioxide by a factor of 10, and even our current position might be unable to support liquid water. A different mix of gases in the atmosphere or different rocks would lead to a completely different cycle from the one on our home world.

> As the star fuses hydrogen into helium and on into the heavier elements, its core contracts. The contraction releases energy and the star brightens. Around 3 billion to 4 billion years ago, our Sun was 30 per cent fainter than it is today. Such a decrease in solar energy should have meant that our planet was 20°C (68°F) cooler than at the present time, and it was largely frozen. Rather confusingly, geological evidence suggests that the Earth had plenty of liquid water on its surface 4 billion years ago. Sedimentary rocks from this epoch have been found that could only have been created by solid particles settling out of a liquid. This problem is known as the faint young Sun paradox. The solution to this issue is still debated. One possibility is that our atmosphere was very different billions of years ago, containing a higher fraction of greenhouse gases capable of holding heat. The carbon-silicate cycle may have allowed carbon dioxide levels to rise as high as 80 per cent of the atmosphere mass. Alternatively, early bacterial life forms may have produced a high content of methane.

> As Mars's core cooled, the convection flow between the mantle and core stopped. Any plate tectonics ground to a halt and the magnetic field died. The magnetic field may have been given an extra death push by a major collision with a moon-sized object that struck Mars more than 4 billion years ago. At only few hundred million years old, the young planet was smacked so hard that it created a dichotomy between the two hemispheres of the Martian crust. The northern surface of the planet is an average of 5.5km (3.4mi) lower than the southern surface, with a crust that is 26km (16mi) thinner. A collision of this magnitude would have generated a huge amount of heat on the impacted northern side, resulting in a temperature gradient across the planet. This might have disrupted the convection flow through the planet's mantle and throttled the magnetic field. The soaring temperatures at the impact site would have demagnetised the rocks in that area, explaining why the magnetised rocks are found predominantly on the planet's southern surface.

> Further observations of Gliese 581 had recorded unusual magnetic activity on the star's surface. The magnetised patch was similar to a sunspot and was interfering with the surrounding flow of stellar material. As the star rotated, the spot appeared as a periodic wobble that looked strongly like the influence of a planet. When this effect was removed from the data, Gliese 581g vanished. What was worse, the correction also erased Gliese 581d.

> There are two problems with finding a transiting Earth-sized planet in the temperate zone. The first is that a planet and star analogue to our own has only a 0.1 per cent chance of transiting. From most viewing angles, the small and distant Earth does not cross the Sun's face. The second issue is that the decrease in light as the planet crosses the star is just one part in 10,000

> Unlike larger Sun-sized stars, a forming red dwarf can be 100 times brighter than its normal dim value once it begins to burn hydrogen into helium. If a planet has formed during this early phase, any surface water could be evaporated away before the star cools.

> the speed of the planetesimals and embryos. These rocky bodies move rapidly on close-in orbits. The final planet-formation stage may end up being dominated by high-velocity collisions, capable of stripping away atmosphere and water from a young world.

> A pure iron Earth-sized world would have a mass of nearly 4 Earths, while one dominated by ice might only weigh in at 0.32 Earths

> Based on the 2,300 planets that had been discovered by the Kepler Space Telescope by 2013, it was estimated that one in six stars had a planet within 80–125 per cent of the size of the Earth. Around the Milky Way's 100 billion stars, this would mean that 17 billion Earth-sized worlds are out there.

> From an examination of nearly 4,000 dwarf stars, just under 40 per cent have a planet that is likely to be rocky; 15 per cent of these were also within the temperate zone of the star.

> A 10 Earth mass rocky planet risks not having exposed continents unless it is very dry, with at least 10 times less water than our own planet. A larger version of our own Earth may therefore always be a water world.

> The Earth's seas have absorbed 10 times more carbon dioxide than is present in the air. This would also happen on an ocean world, but it turns out that the mechanism is the Devil's thermostat. Sea absorption of carbon dioxide is most efficient when the temperature is cooler. If the planet's temperature rises, the sea will draw less carbon dioxide from the atmosphere and allow more heat to be trapped. Should the reverse happen and the planet cools, the sea will increase the removal of carbon dioxide and let more heat escape. Rather than countering a change in the planet's temperature, the endless oceans will accelerate it.

> we do not know how much water is stored in the Earth's mantle. If it is approximately the same quantity as that of the surface oceans, then a 10 Earth-mass planet with plate tectonics could avoid a water world's fate

> Oxygen flooded the atmosphere in a juncture referred to as the Great Oxygenation Event. Unfortunately, most of the populations on the early Earth were anaerobic bacteria that have a toxic response to oxygen. They died in droves, wiping out a huge chunk of life on the planet. Meanwhile, the oxygen in the atmosphere reacted with methane to produce more carbon dioxide and water vapor. While both these products are greenhouse gases, neither is as effective at trapping heat as methane. The removal of methane therefore caused the temperature on the Earth to plummet, producing the massive Huronian glaciation that is our oldest known ice age. During this time, our planet may have become almost entirely frozen, creating a snowball Earth.

[Otherwyrld · Rating 4 out of 5]

This was a great book which not only covered the current search for exoplanets, but also looked in detail at how planets are formed. Not only that, it used reasoned explanations as to how some of the weirder exoplanets (such as hot Jupiters) may come to exist. It turns out that there seems to be almost an infinite variety of types of worlds out there, depending on the enormous number of variables in star and planet formation.This may be bad news for people looking for another Earth because this book pretty much suggests that we won't find one, there are just too many variables to come up with something even close to our own world. This isn't to say that there aren't inhabitable (and inhabited) worlds out there, but we might have to work a lot harder to actually live on them than we would like to think about.

There's a fair amount of technical detail but it is generally handled in a breezy and informative manner, and most people should be able to follow the authors arguments with little difficulty. The author draws no conclusions, but presents us with the facts as they stand at the moment. The only real issue with a book like this is that it lies in such a fast changing science that a lot of the information may be either outdated, superseded or proven wrong within a short space of time.

Still, if you are interested in the subject, this book is well worth the read.

[Jeremy · Rating 5 out of 5]

A terrific overview of current thinking on planetary formation, drawing both on knowledge of planetary science gleaned from our own solar system and observations of exoplanets. I appreciate both the emphasis on the observations and measurements our thinking is based on and the recognition that there is no settled and well-understood vision of planetary formation. Highlights the amazing strides made in this area of science without glossing over the many mysteries that remain.

[S Klotz · Rating 5 out of 5]

I started reading this as I grieved a friend I'd talked about astronomy with over the years.

My love of astronomy was cemented as a core piece of my personality the Summer of 1995 at the month long Governor's School @ William and Mary University. Many of the concepts touched on in this book were first encountered then.

For many years after I finished my physics BS and moved out to California my Mom bought me popular science books like this.

All of that was in the mix every time I read a chapter over the course of 2019. The running theme that blows my mind about the science of exo-planet hunting is how much information is extracted from such tiny data points. A dip in brightness of a star says so much. I feel the author did the same thing with the topic.

Most of us have a picture in our mind of a planet orbiting our sun. Some of us really think about the moon whenever we see it in the sky. This book provides the birds and bees of how planets are made. It uses that foundation to breakdown the exo-planet headlines over the last few decades. It reminds us how many projects and devices have contributed to this particular slice of astronomy.

It's not lost on me that many of the topics hint at how we might make our planet uninhabitable in the coming centur(ies). There are those who dismiss climate science and one of the many reasons I pity such individuals is that they'll never get the chance to appreciate this book.

I tend to not binge popular science books. I read a chapter and then put it aside for a week or a month. Many don't survive the process and are left unfinished. This one, I'm tempted to start a second read-through in the new year.

[Kenneth Sutherland · Rating 4 out of 5]

Very very fascinating book about planet formation and the hunt for earth-like exoplanets. Starting with our galactic origins, Tasker walks you through pretty much every conceivable planetary arrangement, conception, and viability as an earth like alternative for life. (Lot of crazy stuff out there)

Not knowing much about literally anything this book covers beforehand made this an extremely compelling read and Tasker does a great job of explaining what I assume to be extremely complicated concepts in a way that is highly accessible and lighthearted.

[Julian Onions · Rating 5 out of 5]

An excellent description of the modern theory of how planets are made, what planets we know about out there in the galaxy, and the chances for life. I bought the (signed) book after listening to a talk she gave on the subject, and it has the same clarity. Written in a very readable way, and even has an appendix on the TRAPPIST-1 system.

[Chris watson · Rating 4 out of 5]

Nice read

Don’t hesitate to take this journey of exoplanets. Just technical enough to please the nerd but with enough story to make the prose smooth and enjoyable

[Scott Holstad · Rating 4 out of 5]

Pretty interesting topic, pretty interesting book. Not necessarily the best I've read on this, but darn close. Definitely recommended.

[Cristina · Rating 4 out of 5]

In a fantastic primer for budding planetary scientists or armchair explorers, astrophysicist Elizabeth Tasker shares her passion and expertise for the astronomical sciences. Planet Factory chips away at the mountains of exoplanet research and presents it in approachable chunks of historical context, current research and exciting conjecture. Tasker describes how celestial bodies emerge from swirling space dust, details prevailing theories for the varying compositions of known planets and explores the incomprehensibly strange worlds that exist in distant systems (hot Jupiters, super Earths and rogue planets, oh my!).

There were some stretches of text in the middle that felt a bit tedious and recursive, going through the litany of possible explanations for any findings that didn't fit neatly into the currently accepted theories. But hey, that's science! The repetitive circular critique of hypotheses is both a strength and weakness in the text: it was honestly very refreshing to have each theory delineated with a little dollop of doubt, teaching the reader to question and critically assess previous explanations when presented with new evidence. It's even addressed point-blank in the introduction: any scientist trying to report this amount of interstellar research as fact with the pretense that 'we've got it all figured out' is doing a disservice to the reader and to the field. Overall, this book is a very friendly introduction to the awe-inspiring mysteries of our universal neighbors.

Sidenote: I was a little surprised to see no mention of the TRAPPIST-1 system until I realized that announcement was just made February of this year so of course the author didn't have time to cram in a whole new chapter of reactions to these 7 little buddies and their ultra-cool dwarf. That said, this book leaves me feeling well-equipped to tackle the news of exoplanet discoveries on my own.

// disclosure: NetGalley ARC

[Ria Voros · Rating 5 out of 5]

The Planet Factory is filled with fascinating information about exoplanets and what properties they might have, but it's also funny and charming and readable. Elizabeth Tasker takes care to engage her reader and to show that science writing can be--should be--about curiosity and descriptive explanation, especially if that explanation is at a level that non-scientists can understand.

I loved this book and I can't wait for the new chapter that's going to be in the paperback edition in April 2019.

[Anant · Rating 5 out of 5]

A great book that gets you hooked to the wonders of the universe and the strangeness of the planets. Truth is really stranger than fiction.

[Marko Simunovic · Rating 5 out of 5]

I personally loved it.
Amazing insights into the mechanisms needed to form all the different types and sizes of planets (of which there are insane ones all around). At times it could be a bit exhausting to go through the pages when the science and physics get heavily referenced but that is more of a comment on my lack of education than a reflection on the book itself.
In any case it was a very fun and entertaining read that made me realize I need to learn more "fundamentals" when it comes to astronomy :D
The writing itself is to the point, fun, often comic and easy to follow without any distractions other than a relatable example.
Lovely book for any planet lover.

[Carmel-by-the-Sea · Rating 4 out of 5]

Do najciekawszych pytań natury naukowej, które można sobie zadać, zaliczyłbym problem istnienia życia poza Ziemią. Postęp w badaniach planet poza Układem Słonecznym (nazwanych egzoplanetami) dokonany w ostatnim ćwierćwieczu sprawia, że to pytanie nie jest już abstrakcyjną spekulacją czy tematem powieści SF. Astrofizyka planetarna jest obecnie jedną z najbardziej obiecujących i najdynamiczniej rozwijanych się interdyscyplinarnych nauk. W poszukiwaniu obiektów dających szansę na warunki do życia, zaangażowani są biofizycy, chemicy czy geologowie. Setki odkrytych egzoplanet prześwietlana jest pod każdym możliwym kątem. Stosowane techniki pozwalają wykrywać subtelne zjawiska i spekulować o światach odległych od nas o setki lat świetlnych. Ogromne naziemne teleskopy o zwierciadłach przekraczających 10 metrów i najnowocześniejsze orbitalne obserwatoria (Kepler i Spitzer) przesuwają granice badawcze i przenoszą naukowców w rejony dotąd nieosiągalne. Polski flagowy projekt OGLE, który wprost wykorzystuje ustalenia teorii względności, również wydłuża listę znanych planet.

„Fabryka planet. Planety pozasłoneczne i poszukiwanie drugiej Ziemi” astrofizyczki Elizabeth Tasker jest pod kilkoma względami unikatem na polskim rynku wydawniczym. Ujmuje w sposób kompleksowy problem poszukiwania egzoplanet, dając wgląd w bardzo aktualny stan badań (na koniec 2016). Autorka zgrabnie we wstępie opisała ogólne metody poszukiwania planet i obecny stan wiedzy o dynamice i historii naszego Układu Słonecznego. Rozumienie tego najbliższego nam otoczenia, uległo licznym zmianom właśnie w wyniku zdobytej wiedzy o innych układach planetarnych. Przez setki lat znaliśmy zaledwie jeden układ planet krążących wokół gwiazdy. Teraz nasza wiedza dotyczy setek takich konfiguracji. Tasker pokazuje, że sporo rzeczy, które wydawały się niemożliwe, realizuje się w kosmosie. Planety mogą zmieniać się kolejnością na orbitach, mogą tracić gazowe otoczki przemieniając się z ‘jowiszopodobnych’ w ‘ziemiopodobne’. Naturalne satelity gwiazd mogą zsynchronizować okres obrotu z okresem obiegu i stale być skierowanymi do gwiazdy centralnej jedną połową. W efekcie część planety może mieć temperaturę -100 stopni, a inna +1500.

Sporo miejsca autorka poświęciła na przedyskutowanie kilkunastu najbardziej spektakularnych układów planetarnych. Zdumiewająca jest chociażby planeta 55 Cancri e, której atmosfera może być cyjanowodorowa, może zawierać diamenty i zachowywać się bardzo 'nieziemsko' (str. 174-177) . Każdy przykład jest wybrany w sposób bardzo przemyślany, tak by pokazać różne możliwe warianty 'innych światów'. Wszystkie budują dość spójną wizję możliwości realizowanych w kosmosie.

Ostatnie rozdziały zmierzają do punktu kulminacyjnego, czyli do dyskusji nad możliwością życia w kosmosie i naszych ludzkich szansach na jego odkrycie. Tasker fachowo opisuje w nich, czego nowego w obserwacjach powinniśmy się spodziewać w najbliższej przyszłości, jakie warunki muszą spełniać planety, by życie (w wersji nam znanej) mogło zaistnieć. Przy okazji świetnie nakreśliła aktualny stan rozumienia obiegu gazów i ciepła w ziemskiej atmosferze (brawurowy opis efektu cieplarnianego na str. 287-290), a następnie odniosła tę wiedzę do egzoplanet już odkrytych.

Książka napisana jest prostym językiem, choć pewne fragmenty (szczególnie podane w pierwszej części przybliżającej zmienność dynamiczną orbit planetarnych) są nieco bardziej wymagające. Na szczęście jest pomocny słowniczek wyjaśniający kluczowe pojęcia. Tasker bardzo pilnuje, by jasno oddzielać aktualny stan badań od bardzo prawdopodobnych spekulacji, a te od zwariowanych koncepcji naukowców. Przy okazji dokonuje kilku ciekawych spostrzeżeń, które zainteresują fanów SF. Przedyskutowała kilka literackich i filmowych wizji układów planetarnych. W szczególności pewien układ planetarny przypominający 'gwiezdnowojenne' Tatooine (str. 219-221). Opis możliwości istnienia planet w układzie alfa Centauri z kolei powinien dać do myślenia fanom fantastyki Cixin Liu (str. 165-169, 213-219). Sporo z wyobraźni pisarzy należy po prostu brać z dużym dystansem.

Ponieważ "Fabryka planet" wpisuje w szerszy kontekst nasze istnienie, taki nieosiągalny nauce obserwacyjnej 30 lat temu, to warto po lekturę sięgnąć. Pasjonaci podróży międzygwiezdnych, eksploracji innych światów, fantastyki i wizji zasiedlania obcych słońc dostaną fachowe ramy, w których porusza się nauka. Dodatkowo pojawia się kilka polskich akcentów. Tasker szeroko relacjonuje odkrycie Wolszczana (str. 178-198) oraz polski projekt poszukiwania planet metodą mikrosoczewkowania grawitaczjnego - OGLE (str. 212-214). Szkoda, że nie pada nazwisko nieżyjącego już twórcy tej metody profesora Paczyńskiego, jednego z najsłynniejszych XX-wiecznych polskich astronomów.

Gorąco polecam wszystkim. Może nie jesteśmy jednak sami w tym Wszechświecie?

BARDZO DOBRE - 7.5/10

[Adam Whitehead · Rating 5 out of 5]

Up to the early 1990s, the discussion of how life is formed and how many habitable planets there may be in our galaxy was massively restricted by us having only one star system - our own - and only eight planets and two dwarf planets to study. In the last quarter of a century, that has radically changed. 3,710 confirmed planets circling other stars have been discovered, with an additional 15,000 suspected to exist and awaiting verification. We have gone from having a handful of planets to look at to veritably drowning in them, with more discovered almost every month.

The key question is can any of these planets harbour life, even intelligent life, and if they do how can we find them? And how do you build a planet and a solar system anyway?

Astrophysicist Elizabeth Tasker tackles a large number of questions in her book. It looks at how the Earth was formed and the role played by the rest of the Solar system in its creation. This involves a detailed look at the phenomenon which, highly unusually, resulted in our gas giants ending up in quite distant orbits from the Sun (most gas giants end up orbiting their stars at a mere fraction of the orbit of Mercury, becoming so-called "hot Jupiters"), allowing the Earth to form unmolested in the inner Solar system. The book also looks at how water is formed and gets deposited on planets, and the degree to which water is essential for life or if other substances could be used.

The book also explores several dozen of the more exotic exoplanets, including worlds which orbit pulsars and are fried in their radiation beams on a regular basis; worlds covered in thick tar and others where diamonds literally rain out of the sky. There are water worlds with oceans thousands of kilometres deep and frozen iceballs which have been catapulted out of their parent systems and now wander on their own between the stars. These descriptions are vivid and show how chemistry and physics can combine to create worlds far stranger than any science fiction has come up with.

The book is approachable, with occasional dips into more complex discussions of chemistry and orbital resonances, but for the most part the book is perfectly readable for the layman. There's a nice line of humour in the book and the use of pop culture references to explain how certain planets work (a chapter on exomoons compares them to the Forest Moon of Endor from Star Wars, for example, and the one on rogue planets briefly invokes the Transformers homeworld of Cybertron which was likewise blasted out of its orbit around its home star).

The book also explains the techniques used for detecting exoplanets and how they are being refined further to look for planets the size of the Earth, or smaller, and how we may be able to pick up the telltale signs of life through atmospheric conditions.

One of the things I liked most about the book was its upbeat tone. Given that exoplanets seem to have added a whole load of extra steps to the conditions necessary to have life, it would have been easy to have concluded that if life is out there, it's even rarer than we thought and would be very difficult to find. However, Tasker instead keeps showing how even the craziest worlds may still be able to give rise to (at least) bacteriological or microbial life. In one of the most positive chapters, she even looks at the problems Earth has had in developing life - its frequent ice ages as the result of Milankovitch cycles caused by the gravitational tugs on its orbit by other planets, its occasional collision with large asteroids - and postulates planets that wouldn't have these problems and where life and even intelligent life could develop much more quickly than on Earth.

The Planet Factory (****½) is a fast-paced and readable non-fiction book which expands on current science, explains planet formation theories in an approachable way and is highly informative. It's also a good watch of catching up on what is a very rapidly-evolving field. The book is available now in the UK and USA.

[Russell Atkinson · Rating 4 out of 5]

The author has attempted to make a captivating but very technical subject accessible to the general reading public, with mixed success. I found it fascinating, but I have a math degree and was an A student in physics and astronomy; I suspect that others might find it too dense. The author makes a valiant attempt to make basic concepts understandable, including use of a great many metaphors and similes from everyday life, especially in the early chapters. Some of these could be helpful, I suppose, but I found them at times condescending (do we need to spin in an office chair with arms outstretched to understand you spin faster if you bring them in?), at times amusing, and occasionally confusing. The author often uses British colloquialisms for these, leaving a poor American like me to discern from context that a roundabout is not a traffic control device but some sort of merry-go-round. As for throwing a jelly at someone, I have no idea what that means; wouldn't the jar crack his noggin?

Quickly, though, the author moves into the details of planet formation, fortunately without the equations. Rather, we must take her word, and that of countless other scientists, as to what is possible or impossible. For the 99.999% of us who can't do the calculations ourselves, Clarke's Third Law applies: the rules of planet formation are indistinguishable from magic. The problem with this is that what we/they thought was impossible is now being observed in distant star systems. Huge gas giants are orbiting very close to their stars. So are rocky superearth planets where they should not be able to form. There are planets whose density is between those of the rocky planets we know (Earth, Mars) and the gas giants we know (Jupiter, Saturn). So what are they made of? Water? Silicate rock? A rocky core surrounded by gas? What we "knew" about planets isn't true anymore. The author explains all the theories that the experts have come up with, but she states right up front that we really don't have good explanations for much of what the observational science is producing. The exciting part is that we are finding more and more exoplanets. New discoveries bring new knowledge.

If you are primarily interested in whether there is life out there or a planet capable of hosting us after we destroy the one we're on, you'd be advised to skim liberally up to the last few chapters where these questions are addressed more directly. The short answer is that alien life is certainly possible, maybe probable, but it is unlikely to be in a form we could ever communicate with or even observe. A place where we could relocate would have to be closer to home and the only candidates seem to be moons within our own solar system, although none of them look all that promising. Still, it is amazing to consider all the factors that life as we know it require and how lucky we are to be in that Goldilocks zone. Once you do that, then consider those organisms like tube worms and anaerobic bacteria that do not require sunlight or oxygen. Life has a way of adapting to some very inhospitable environments.

The author and publisher have bravely aimed for what seems to me to be a very small slice of the reading public. The book is too simplified for researchers in the field and too technical for most other readers. She writes very well but there are a few errors. On p. 232 she states that the temperate zone in our solar system is conservatively estimated at 0.84au to 0.14au. That second number should be 1.14au. Otherwise we wouldn't be alive. All in all I really enjoyed the book but I find it hard to recommend to most people. What I can say is that when you see the next headline that reads "Second Earth Found!" don't believe it.

[Kevin Prinoski · Rating 5 out of 5]

The Planet Factory" (2017) written by astrophysicist Elizabeth Tasker (whose initials are ironically "E.T.") discusses various planetary morphologies, modes of planet formation, and the on-going search for exoplanets. Tasker notes: "As I write this, there are 3,439 confirmed extrasolar planets..." - from roughly three years ago. As of this month (March 2020), that number has climbed to 4,135 (refer to NASA Exoplanet Archive online). This book is equally fascinating in content and humbling in perspective as it points out the crucial aspects of our planet and solar system that made and continue to make our very existence possible. The structure of our planet is conducive to life as it orbits within a habitable zone around the right type of star, and at the right time in that star's life-cycle. Also, the structure of our solar system is critical to life on Earth and said structure, though likely not unique in our galaxy, certainly is "not normal", as Tasker points out.

Also discussed are the characteristics of our solar system’s inner planets which render them currently biologically inhospitable, as well as tantalizing possibilities for life elsewhere, such as Jupiter’s Europa and Saturn’s Enceladus. Both of these moons appear to contain vast quantities of subsurface water, as well as an energy source - tidal flexing due to the gravitational influence of their respective host planets. Tasker closes with an insightful explanation of how extraterrestrial life might differ from life on Earth. As plants evolve to use wavelengths of light based on component photon quantities or energy properties (or both), plant phenotypes will therefore be influenced by characteristics of the host star and planetary atmosphere. For example, photosynthesis driven by cool red dwarf stars might result in plants that are black instead of green as they strive to absorb as much of the weaker light emissions as possible. Planets with host suns more luminous than our own might have the opposite problem as their plants are exposed to more high energy photons. Atmospheric considerations aside, plants under these conditions might develop a blue tint as they strive to reflect excessive numbers of higher energy blue photons and minimize biological damage.

This book surveys current data and theory with sufficient explanation to foster understanding and keen interest - highly recommended!

[David · Rating 4 out of 5]

The author of this book, Elizabeth Tasker, is a British astrophysicist who works primarily in the area of computer simulation of star formation. The Planet Factory, her first book, was published in 2017, and updated in 2019, which makes it a little behind our current knowledge. Nevertheless, there was a great deal in it which was completely new to me, and I found it absolutely fascinating.

Now, this is a bit of a digression. I want to start by admitting that I’m old. I’ll very shortly be 73 years of age. Younger people may therefore have trouble understanding how profound a change has occurred in our knowledge of astronomy since I was at school, sixty-odd years ago. But I’d like to take you through it from my point of view and hope not to bore you in the process.

I clearly remember looking with fascination at photos of the planets in some kind of illustrated science book when I was in primary school. The best photos of Jupiter and Saturn in the book were very fuzzy ones in monochrome, showing little detail. Yes, you could see that there were bands of different shades of grey and a darker big spot on Jupiter; and the shape of the rings of Saturn were obvious. But that was it.

At school, we were taught a theory about how the Solar System came to be: another star passed close to the Sun and drew out a long filament of matter from its surface, like a long hot sausage, thicker in the middle than the ends. This then broke up into the individual planets. Obviously, such an event would be an extremely unusual and unlikely one, and therefore planet formation would be a very rare occurrence. This is the Tidal Theory proposed by Sir James Jeans in 1917, and by the time I was taught it, it should already have been considered well out of date; but education lags behind current thinking as a matter of course. I was also taught that the craters of the Moon were those of now-extinct volcanoes. The idea of them being impact craters was yet to be accepted.

Naturally, since I’ve always been interested in science, as I grew older I kept on top of most of the latest thinking and knowledge, and was thrilled by the incredible photographs taken of the outer planets and their moons by the Voyager probes in the early 1980s. Where previously we had only had fuzzy photographs taken by Earth-based telescopes, on which the moons of these planets were really only dots of light, now we could see close-ups in great and fascinating detail.

When I was young, there was no evidence that there were planets around any star but the Sun (making the Tidal Theory at least plausible, I suppose). Today, because of instruments like Kepler, we know of many thousands of exoplanets, and all the evidence leads us to believe that almost every star in the sky must have its own family of planets. Even more incredible, in many cases we’ve been able to determine the size, mass and sometimes even the atmospheres of these distant worlds.

The Planet Factory discusses these discoveries, and the rapidly-developing ideas about how planets are formed, in considerable and very interesting detail. As more and more exoplanets were discovered, almost every new discovery meant that the current theories of how planets form had to be modified and in some cases completely discarded. What is becoming very clear is that our own Solar System, which we had naturally assumed to be a typical arrangement of planets, is far from typical. In fact based on what we see around other stars, it may be quite unusual. Some of this perhaps is down to a bias towards the kind of planetary systems we can most easily discover, but by no means all of it. And our understanding of how the Solar System itself formed has undergone many changes: new ideas suggest that the giant planets of Jupiter and Saturn may have at one point migrated inwards much closer to the Sun, and only later moved outward again and found their current apparently settled positions. There may well have been a gas giant of the size of Neptune or Uranus which was ejected altogether from the Solar System and now wanders, lonely as a cloud, in the depths of space.

The author then looks at trying to find a “second Earth”, an Earth-like planet around another star in the temperate zone which would allow liquid water and life on its surface. The book shows how tricky and complex this search is, and will continue to be. Planets are extremely complicated things, and as the author says firmly at one point: “an Earth-sized rocky world does not equal an Earth”. As we’ve found with the bodies in our own system, it has been all but impossible in advance to predict what the surfaces of planets and moons would be like in any detail. Apparently minor differences in geology, in composition, in position, in illumination, can create extremely different results on planetary surfaces.

There are times in the book where the level of detail of discussion of alternate theories becomes rather too much too quickly, but overall I really enjoyed what I learned.

Recommended.

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[Andy · Rating 4 out of 5]

I was very excited to pull this book off the shelf when I saw it at the bookstore and didn't hesitate to add it to my cart. I was excited to read it, but I will say that I was curious whether there would be a split focus in the book given the title and subtitle. "The Planet Factory: Exoplanets" seems to promise one topic, and the second half of the title "and the Search for a Second Earth" seems to offer a very different topic.

Fortunately my concerns were unfounded. Professor Tasker starts with the mechanics of the "planet factory" and smoothly slides into the "search for a second earth" as the books progresses towards it's end. For a book of popular science I think it thoroughly treats both topics, even if I personally would have been giddy to see a bit more about planetary formation.

More than anything, this book offers a great survey of the types of worlds that are (or might be) out there in the galaxy. In fact, if I knew any sci-fi authors I would be just as likely to recommend them this book as I would someone who likes astronomy and astrophysics.

The only "qualm" I had with this book was a bit of new-book-syndrome later on in our search for a habitable exo-planet (or moon). When exploring whether a certain type of planet (or planet orbiting a certain type of star) might be habitable, Prof. Tasker may be talking about why the planet is particularly ideal for habitable, expound upon why, and then wrap it up and essentially go "But not all is well! [reason why planet might not be habitable after all]" and then follows an exposition on why this is so. At points it almost seemed cyclical, as in the former example if at the end it was continued with "But yet there is hope! [reason why this previous reason might not hurt the chances of habitability after all]". Regardless, it was a minor thing and almost felt like a running joke, and I guess in a way it sort of kept me on the edge of a seat, as if I was watching a really close tennis match.

Overall, this was a great book on planet formation and I found Prof. Tasker to be a good science communicator. I'll certainly be setting up alerts to keep tabs on any new books by her and will certainly be keeping this on my shelf.

[Charles Sheard · Rating 5 out of 5]

I thoroughly enjoyed this book, which takes a subject of which we humans are only beginning to scratch the surface, and manages to present both our attempts at drawing conclusions from the limited data, and how those conclusions are constantly evolving as new data comes in. And ultimately - that's the scientific process in a nutshell, isn't it? For those thinking they would read exact theories explaining and detailing specific planets that have been discovered, a more realistic approach is to understand that the entire field is barely 25 years old, and the amount of information that has actually been observed for any particular system is incredibly small, so the ability to make thoughtful interpretations and guesses are absolutely still in their earliest formative stages. But personally, I cannot think of a more exciting time to participate in this field of science, with greater possibility for new data, hypothesizing, and advances in observational technology, and I found the evolutions of ideas presented here to be extremely illuminating. I envy my daughter who will be heading off to college next year (2021) to study this very field - perhaps even with some of the researchers mentioned in this book.

As far as Tasker's personality coming through occasionally (some reviewers didn't seem to care for her analogies or humor), I found it refreshing. With the many, many phenomena being discussed (quite thoroughly) and the often quirky nomenclature and jargon, Tasker's personal voice helps humanize the delivery, even poking fun at the nomenclature itself, such as in her footnote on the Thirty Meter Telescope, "Let's take a moment to appreciate the descriptive , yet unimaginative, naming of astronomical instruments." I had the benefit of hearing her voice narrate some Mars2020 information on-line, and enjoyed hearing that delightful accent in my head as I read.

The big question is whether Tasker will provide a sequel in another 10 years or so, with all that we will certainly learn in the coming decade (I'm looking at you, TESS and JWST). I certainly hope so.

[Noémie J. Crowley · Rating 4 out of 5]

Un petit livre de vulgarisation pas prise de tête sur la formation des planètes avec un focus sur les zones habitables ? Je dis oui !

Car globalement, voici le pitch de The Planet Factory : un livre plus ou moins grand public, qui tente d’expliquer l’origine des planètes (leur formation, les changements qu’elles vivent au cours de leur vie, etc), sans s’occuper uniquement de la Terre et des planètes lui ressemblant. C’est un livre qui se lit très bien, relativement vite (un peu moins de 500 pages), et contient plusieurs graphiques et illustrations bienvenues.

Il s’agit vraiment là d’un sujet fascinant, et j’aimerai pour sur lire plus de livres à ce sujet. ProtoTterre ou non, la découverte d’exoplanètes est à mon sens toujours très excitant, et mérite plus d’attention. Si le sujet vous fascine, foncez !


A little, hassle-free popularisation book about the formation of planets, with a focus on habitable zones ? Yes please !

Because overall, this is the summary of The Planet Factory : a more or less mainstream book, with the objective to explain the origin of planets (their formation, the changes they go through their lives span, etc), without putting too much focus on Earth and lookalike planets. It is a very easy and quick book to read (slightly less than 500 pages), and contains quite a few welcome graphs and sketches.

It is a very fascinating subject, and I for sure would like to read more books on that matter. Porto-Earth or not, the discovery of exoplanets is to me always very exciting, and deserves more attention. If you like the subject, go ahead !