The Pale Blue Data Point
by Jon Willis
University of Chicago Press, 2025
Reviewed by Casey Dorman
Jon Willis calls himself an astrobiologist, and he mixes astronomy and the study of organic life in this new book. His purpose is to explore the possibility of finding and recognizing life on another world, either one within our solar system or on an exoplanet orbiting another star. He makes an effort to titillate us with descriptions of unusual life here on earth, such as the oceanic creatures found near deep sea vents and a brief discussion of the communication patterns between dolphins. His most in-depth discussions, however, are related to astronomical observation, both its limits and its promise, as well as what we’re learning from studying the surface characteristics of Mars, Jupiter’s moon, Europa, and the evidence gleaned from asteroids. Particularly with regard to astronomy, the discussions are deep and scientific but made livelier by focusing on his own experiences, as much as the pure science. His language is intimidatingly literate, and I was captivated by the elegance , as well as driven to my online dictionary, by some sentences, such as “A dim, dead star, lit not by the glowing fire of nuclear fusion but instead by a tenebrous revenant limned in the nebular glow of ionized gas trapped within its crushing gravitational environs.”
The Jovian moon, Europa, as well as Saturn’s Enceladus, are ice-covered moons orbiting two of our solar system’s gas giants. Europa seems most promising in terms of exploration beneath its ice, and Willis explores the world around Earth’s deep sea vents to find an analogy. to what that life may be like. I learned that some microbial life can use chemosynthesis to create food and energy, in the absence of sunlight. Deep water shrimp, without eyes, have a sensitive red patch containing red-light sensitive rhodopsin on their backs to detect the thermal photons as infrared radiation in the hot deep sea vents and are able to navigate around their periphery in the cooler, dark waters surrounding the vents. All of these evolutionary developments show that life is sufficiently flexible in its ability to adapt to possibly be present beneath the ice of the gas giants’ moons.
At the heart of the search for intelligent life beyond our own solar system, is the formula developed by Frank Drake, the man behind SETI, in 1961: N = R∗ × fp × ne × fl × fi × fc × L . N is the number of communicating (into space) civilizations in our galaxy. R* is the rate at which new stars are born, fp is the fraction of stars with planets, ne is the number of habitable planets per star, fl is the fraction of those planets with life, fi is the fraction of those planets with intelligent life, fc is the fraction of those that can communicate into space, and L is the “average lifetime of such communicating civilizations.” At the time the equation was developed, no planets orbiting other stars had been found, so all the values for the various variables, except the rate of new star birth, were guesswork. Since then, we’ve found that virtually all stars have planets, a significant proportion of these are habitable in terms of being generally earth-sized and in the so-called “Goldilocks zone” not too far from and not too near their star. A good deal of the book is devoted to exploring the likelihood of a planet developing life. Willis’ method is mostly to understand the conditions on Earth that were conducive to developing life and searching for them in the bits we know about other planets from soil samples from Mars, and geochemical evidence form asteroids. The answer is still a guess, as are the answers to what fraction of planets with life would develop intelligent life and what fraction of that life would choose or be capable of communicating into space. Interestingly, at the end of the book, the author concludes that it may be that the crucial variable in the whole equation is the average lifetime of intelligent civilizations, and our own history, and current situation, suggest that, if we are an example, it may not be long in terms of the life of the galaxy. Most of our own planet’s history had no human-level intelligent life, and climate change and mismanagement of our resources may end our reign on Earth fairly quickly.
Even if there are communicating civilizations “out there” somewhere, what is the chance that we will understand them? Willis uses dolphins, who are intelligent and who communicate with each other, but which we still are unable to understand or communicate with except in a very rudimentary way, as an example of how difficult it may be to understand another intelligent species from space. Still, as he points out, just finding that someone is out there will be a civilization-shaking revelation, should it happen.
The Pale Blue Data Point covers a lot of territory, and the author needs to continually remind us how each new topic is related to the overall theme of finding life somewhere beyond Earth. He spends much of the time discussing the means being used to answer the question and less time on what we know so far. This is partly because we are still at the beginning stages of our search, and many of the needed steps are still hopes and dreams rather than realities. What leapt out at me from the pages of the book was one very clear conclusion. The more we learn about the universe and all the individual instances of how it appears, the less uniform it seems to be. So far, we have encountered a lot of surprises. New stars develop much more rapidly than anyone thought. The geochemistry of the earliest Earth, called the Hadean eon, may itself have produced liquid water and led to the earth having oceans soon after it began to exist as a rocky planet, instead of the vast majority of our early water coming from asteroids and meteorites that struck Earth. Thus, life could have developed earlier than anyone has thought, and perhaps when it did develop that was the culmination of many false starts. What kind of planets, whether rocky or gaseous, and what size can exist at various distances from their stars, is much less predictable than we thought. Discoveries such as pulsars that emit regular pulses of radio waves have been a nearly total surprise. The list goes on and it means that the science of space is still one mainly of discovery, rather than confirmation of hypotheses. Many of our hypotheses will need to be rethought when we find out what is really out there. As the author of this book points out, the lesson should be that what we find, when we find life, may defy our ability to imagine it, even using the best of our current science to frame our expectations.
This is an interesting book, but not one for the scientifically timid or those unwilling to increase their vocabulary as well as knowledge. What the author does best, and much better than most similar books, is show the kind of reasoning that has led to what has been studied so far and what guides our current and future search for extraterrestrial life. The reasoning behind the research is presented clearly. Also, the meaning of what has been found so far is spelled out in ways that are not difficult to understand. The details of the studies and the findings are often abstruse, but the overall picture is clear. This makes it worthwhile to read.
Interested in scif-fi about AIs solving moral dilemmas in a future that has them exploring our galaxy? Read Casey Dorman’s Voyages of the Delphinovels: Ezekiel’s Brain and Prime Directive. Available on Amazon. Click Here!
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As Spock would say, “Fascinating.”
While this book would be beyond my level of comprehension, I know exactly who in our family would love this for Christmas.
In addition, this review, while humbling, took me at least “a fraction of an inch” further in trying to wrap my head around the “awesomeness” of it all!