The Geography of Space Exploration: The Search for Life on Mars (Book Review)

Danny Bednar, PhD
11 min readMar 18, 2021


Howell & Booth’s book serves as an anthology of personal Martian stories, revealing that behind the search for life on Mars lay entirely Earthly processes. If you’re looking to really brush up on the science of Mars and the search for life it is a must read.

Danny Bednar, PhD, is Canada’s second-best geographer of space and an Assistant Professor in the Department of Geography at Western University. He works 9 to 5 at the Canadian Space Agency and is an author with Mango Publishers. All views are his own.

The Search for Life on Mars by Elizabeth Howell and Nicholas Booth (Arcade, 2020) available now from you local independent book store (Image: Simon & Schuster)

Whether there is, or ever has been, life on Mars remains a pressing question in planetary science. However, the reason as to why one might care about this question may vary.

For myself, and perhaps others with no theological inclinations, the question is largely an existential and scientific one. Knowing if there is, or ever has been, life on Mars would serve as an important bit of information in understanding the evolution of the solar system and just how much of a fluke life’s presence on Earth is.

Necessarily, a question that follows from this line of inquiry is whether discovered Martian life would be entirely indigenous to Mars, indicating a sort of second ‘genesis’ event in which the spark of life emerged twice in one solar system (that’s a Star Trek reference, not a Christianity reference). Conversely, if Martian life ever existed, there is the possibility that it was/is a relative of Earthly life, born of the same processes that created life here and somehow spread from one planet to another.

For starry eyed dreamers and escapist Mark-Watney-larpers, the question of life on Mars is a bit more practical. If there is, or ever has been, life on Mars, it’s discovery may hold clues as to how humans could potentially stay there for a few weeks/months at a time in the distant future. If there is life on Mars right now, it is likely reliant on some form of yet-unidentified energy or stored hydrocarbons. Both of which would be necessary for humans to not die shortly after landing on the hellhole that is the Red Planet.

Regardless of why you care if there is life on Mars, you are beholden to rovers currently on the planet’s surface, the satellites sent to orbit it, and most critically, the humans back on Earth that operate and interpret the results from these machines. At the end of the day, it will be these humans, and their interpretations, that answer the question of life on Mars.

Like all science, the search for life on Mars is neither as objective nor as definitive as popular social discourse implies. The answer to this question relies fundamentally on interpretations.

Enter Elizabeth Howell and Nicolas Booth’s new book: The Search for Life on Mars: The Greatest Detective Story of All Time. Part planetary science textbook, part anthology of biographies, the book is a wonderful historical, and present-day, analysis of Martian science. The book’s strength comes from the access the writers had to experts involved in Martian exploration as well as a significant amount of archival research.

Audience wise, I would suggest this book for experienced space readers or casual space fans looking to really challenge and sharpen their Martian knowledge. It is not necessarily an introduction to Mars science as there are a few things you may need to look-up (I certainly had to). But the book’s depth should be seen as a strength rather than a weakness.

Building robots to search for life on a planet 2,500,000 kilometers away isn’t easy. Any interested readers owe it to themselves to learn about about these things with a degree of rigor representative of the challenge. I was keen to take on the challenge of brushing up on, and adding to, my Martian knowledge, Howell and Booth’s book offers ample opportunities.

As I often do, I approached the book as an educator. I teach about space exploration at the university level and am always interested in new sources to provide my students. As I’ve said, The Search for Life on Mars has an anthology feel to it, perfect for myself and other instructors looking for topic- or event-specific readings that tell a confined story within the chapter. That being said, the book does flow as there are natural narrative links between most of the chapters. For those further interested, a detailed breakdown is below. I have included just a sample of the dearth of information from each chapter as a sort of appetizer for those looking to greatly expand their Martian knowledge.

The Search For Life on Mars by Elizabeth Howell and Nicholas Booth is available now from your local independent book store and wherever good books are sold.

The Search For Life on Mars: Chapter by Chapter

A portrait of landing sites on Mars and the NASA missions that call them home. These robots, and their kin orbiting high above the Red Planet, are one half of the key characters in the Search for Life on Mars (Image: NASA)

Chapter 1: Frozen in Time explores the nature of the Martian climate, it’s poles, and the question of subsurface ice/CO2. The chapter doesn’t focus too much on any one mission, with references to Mars Global Surveyor (1996–2006), the Phoenix lander (2007–2008), and the failed Mars Polar Lander (2000).

Chapter 2: Inside Out is, pardon the pun, an fun dig into the inside of Mars and one of the newest robots on its surface. Essentially a chapter about the recent NASA Insight mission (2018-Present) and a fascinating exploration of the nature of ‘Mars quakes’. The chapter outlines the mysteries surrounding where exactly seismic activity is coming from and how it might be created given there are no plate tectonics on Mars. The extent to which Insight is detecting seismic activity is astonishing. Mars is noisier than the Insight team expected it to be. Among the many mysteries sprinkled throughout the book, Insight contributes a puzzling relationship between subsurface activity and the time of day, suggesting perhaps that solar energy is affecting sub-surface ice, creating shifts and slips that register on the incredibly sensitive instruments onboard. Time will tell.

Chapter 3: Curiosity is, shockingly, about NASA’s Curiosity rover (2012-Present). Though, its about more than that. The chapter also explores the location where Curiosity landed, Gale Crater. Curiosity’s landing site is a giant crater with a mountain in its middle that was at some point, in the distant past, filled with water. The chapter is a wonderful recounting of the challenges of landing on Mars and the tricks needed to get it done (for example, turning off all receiving capabilities on the rover/spacecraft as it descends to the surface so that the automated landing system doesn't pick up any errant signals).

This chapter really signals where the book shifts its focus towards the humanity behind Martian robots as the chapter includes an excellent immersion into the operations room for Curiosity. While I’ve never sat in on active planetary missions, I have been a part of analogue (practice) rover missions and indeed the dynamic of mission control is incredibly fun and stimulating (though probably a bit more stressful when real). From explaining how virtual reality tech is being applied to immerse rover operates in the Martian environment to shining a light on the way differences of opinion influence rover operations (such as where the chlorine may on Mars be and how it got there) Chapter 3 really starts to show the true moral of the book: behind every robot is a team of humans.

All the missions we send to Mars are not only operated by humans. Robots will never tell us if there was life on Mars, we’ll have to decide that amongst ourselves based on the data.

Chapter 4: Road to Utopia (Viking Program and the History of JPL) is the chapter I, IMHO, would have kicked off the book with. It is part history, part biography, and maintains the thread of exploration, personality, and mystery that the story is structured around. One of my favorite chapters, it’s historical accounts do well to avoid space-race clichés overtrodden by most space writers. Howell and Booth instead focus on capturing the feeling of being at JPL during the Viking era (1975–1980) and just how much things have changed.

A Mock-up of the Mars Viking Langer back on Earth (NASA/JPL)

Chapter 5: The Measure of Mars (Mars Reconnaissance Orbiter & Phoenix Lander). Another wonderful historical chapter, the authors paint the long and winding road that was the emergence of new Mars missions after the dark decade of space exploration in the 1980s. The chapter also brilliantly outlines something key to understanding all space exploration, the evolution of camera systems and how they are designed. A largely underdiscussed aspect of space exploration, I truly commend Howell and Booth for taking on, and brilliant narrativizing, the history of these instruments and their development for space missions.

Not only do Howell and Booth provide a much needed story of why cameras designed for Mars came along, they intertwine these developments with Martian science, namely the identification of Hematite on the surface. On Earth, hematite is typically found where there is, or was, water.

From the perspective of a geochemist, areas of Mars that are rich in hematite are good candidates to have once been covered in water. Where there was water, they may have been life. With these observations in hand, Chapter 5 provides background on the evolution of the now famous “follow the water” logic that has directed a fleet of Mars rovers since the turn of the century.

An artists conception of the Mars Reconnaissance Orbiter (MRO) which arrived at the Red Planet in 2006 (image: NASA/JPL)

Chapter 6: The Pathfinder (Pathfinder & Sojourner). The most personal chapter in the book, it centers on space exploration trailblazer Donna Shirley and her work on the Mars Pathfinder mission (1996–1997) as well as its accompanying rover Sojourner. Given that chess is all the rage this year, readers might be fascinated to learn the story of the little rover that could had a CPU modelled on the IBM Deep Blue computer that defeated chess champion Gary Kasparov in 1997.

An artists mega-90s depiction of the the Pathfinder lander and its accompanying rover Sojourner (Image: NASA/JPL)

Chapter 7: Waterworld. No one mission is particularly the feature here, but the Mars Reconnaissance Orbiter (MRO) (2005-present) might come closest. The ever fascinating question (at least for planetary science nerds) is where did Mars’ water go?

Up ? Indeed, it could have evaporated upwards into the atmosphere and then into space as the Red Planet looses its gases to space due to a lack of magnetic shielding.

Down? Possibly, some people are brave enough to suggest that tons and tons of it (literally) seeped below the surface and froze in place as large sub-surface ice deposits…we’ll see.

Around? Sure, we know Mars has polar ice caps, but just how much of their makeup is the result of the planet’s atmosphere condensing at the poles and precipitating down as snow into giant ice caps?

No one knows…

Artists interpretation of what an ancient Jezero Crater on Mars could have looked like. Hypothesis of a lake filled crater with inlet and outlets was a defining facto in this crater’s choice as landing site for NASA’s Perseverance Rover in 2021 (Image: NASA/JPL)

Chapter 8: Claims. Again moving away form a singular mission focus (though Viking gets a fair share of attention) Howell and Booth turn the history of extraordinary claims of extraordinary evidence. Martian canals have been a oft-treaded area of discussion, so the authors do well to use them as a point of entry into the wider topic of past claims of life on Mars. A strong candidate to be a course reading due to its quick summary of major events.

The issues in this chapter are always important for geographers and our concepts of place making. The Mars canals were an imprint of society that people wanted to see, they were based on loose evidence that was poorly interpreted but nonetheless excited a lot of people. To this very day, hypothesis of grandeur and artists renditions of cities on Mars, equally false and equally fictitious, still excite people. Why?

An image from Viking 1 showing a trench dug by the lander’s scoop. The results of on-the-spot experiment to search for signs of life in the scooped was interpreted to have been positive by a small minority. The ongoing discussion that has evolved reinforces the personal reality of science. It’s all about people and interpretation.

Chapter 9: Reactions. Press sensationalism meets scientific uncertainty with the usual result…aliens! The ever intriguing tale of a meteorite that was found in Antarctica, this little black rock underwent nearly every test in the world after a few geochemist suggested there were features consistent with biogenic (life) processes. NASA held a press conference with Bill Clinton, the news media yelled aliens. Calamity ensued.

An extremely enhanced zoom of a microscope scan of the meteorite from Antarctic known as ALH84001. The rock is hypothesized to have been thrown of Mars by a giant asteroid impact long ago and have eventually landed on Earth. The features within have been considered as possibly, potentially, theoretically consistent with known Earthly geochemical processes that create similar, but not identical, features (Image: NASA)

Chapter 10: Signatures (Perseverance). A late chapter that really reflects the heart of the book. Howell and Booth are kind and respectful to their human subjects, portraying them honestly and positively as keen nerds living a dream. Exploring the then-future mission Perseverance (2021-Present), the chapter contains a factual traunch of information that alone justifies the cover price. Dissecting Percy the Rover’s instruments one by one, there are gems of info along the way, including the fact that NASA’s latest rover, while designed to be the first stage of a sample return mission to bring Martian rocks to Earth, is itself a sample return Mars.

Yup, Perseverance has onboard it a piece of Mars.

How? Like ALH84001, the Sayh al Uhaymir meteorite landed on Earth after being blasted off of Mars sometime in the distant past, likely a few million years ago. After more than a decade of analysis confirming it came from Mars, pieces of Sayh al Uhaymir have been placed onboard as calibration targets for one of the Rover’s instruments (SHERLOC). Since the rover team knows exactly what the meteorite is made of (they checked before packing it), they can be confident that SHERLOC is “dialed in” if it sends back the right info.

But why a Martian meteorite? The meteorite is known the to have the specific wavelengths of light that will reflect off of most Martian material now surrounding Percy. The expected similarities in results from the onboard meteorite and the local environment make the precious package an ideal calibration target (Mars rocks have some unique-ish spectral signals…i.e. reflections).

Artist depiction of the European Space Agency’s Rosalind Franklin Rover expected to land on Mar in the Summer of 2023 (Image: ESA)

Chapter 11: Return to Sender (Sample Return and Future Missions). Everyone is getting in on the Mars science party. While half a ton of Martian material is estimated to land on Earth each year in the form of meteorites, in no uncertain terms, that is not the good stuff. We need primo-quality Mars samples to answer whether there was ever any life on Mars.

Targeting this, Perseverance will collect samples of Martian soil and rocks and then stash the, in sampling tubes for a future rover that will grab the samples and put them in a return capsule. It’s hoped that said future mission would bring home about 500 grams of pristine Martian material (unbothered by flying naked through space or being exposed to Earth’s atmosphere). This is expected to happen sometime between now and the distant future in which humans might land on Mars. If I were a betting man, I’d guess robotic sample return in the 2030s, and anywhere from 2050 to 2090 for a fully successful human mission.

In the meantime we can look forward to the ongoing adventures of a fleet of new rovers and orbiters heading to Mars. Perseverance is already there today, as we speak, unfurling its instrument suite and wandering the desert. More rovers will follow. So, pick up the book, learn all about it and, like the rest of us in the space science community, wait patiently, knowledge in hand, that something big could be discovered any day now.

NASA’s newest rover on Mars, Perseverance, shown here descending to the surface from its delivery vehicle. Perseverance will collect samples and place them in an undetermined location for a future mission to collect (Image: NASA/JPL)



Danny Bednar, PhD

Part time professor and author with a 9-5 at my local space agency. Writing about space exploration, heavy metal, classical music, & hockey.