The Sirens of Mars: Searching for Life on Another World
Review by Clare Fieseler
This is a book about Mars science, yet its narrative holds relevance, and even lessons, for the unpredicted mission now facing the scientific community.
Before Carl Sagan, a polo-playing businessman was the face of extraterrestrial life detection on Mars. Percival Lowell popularised the idea that geometric lines on Mars’s surface were irrigation canals engineered by intelligent Martians. It took the first NASA fly-by of Mars in 1965 to put the theory fully to rest.
The canals of Mars were an appealing cocktail made by one man’s unbridled optimism and an optical illusion. Before his death in 1916, Lowell mapped a geometric web on Venus’s surface, too. In 2003, ophthalmologists provided evidence that Lowell’s map of Venus was practically a carbon copy of the human retina. Lowell, thinking he was mapping other planets, was mapping the inside of his own eyeball.
According to Sarah Stewart Johnson, planetary science is rife with stories of how Mars becomes a mirror, reflecting back whatever is deep inside the scientist studying it, be it optimism or ambition. In this book, she chronicles a multi-generational lineage of scientists who chased discoveries on the Red Planet in patterns of near-obsession and self-revealing behaviour that have escaped most Space Age historians.
Few people are more qualified for this job. At 41, Johnson is one of the youngest people to have contributed to NASA’s new Perseverance rover and its two previous Mars rovers. I should say that she and I taught in the same department at Georgetown University from 2018 to 2020.
The narrative core of her book starts with Lowell and his Mars canals. But Johnson also goes back to Galileo, “to whom Mars appeared as only a poppy seed,” and describes how our first understandings were layered from the ground up by 19th century scientists and balloon-traveling adventurers who were all limited to the telescope.
The narrative arrives at the first Mars missions of the 1960s with sharp details and exuberant anecdotes. The first, Mariner 4, was a NASA fly-by that took digital images so shockingly similar to the Moon’s surface that the New York Times declared it a “dead planet.” Later missions, like Mariner 9, mapped 20 per cent of Mars’s surface, finding that it had pocketed moonscapes but also ancient riverbeds, reigniting hope that Mars had water after all. Johnson covers the drama of NASA’s Viking programme, the first Mars landers, like a soap opera filled with breakthroughs, budget cuts, untimely deaths, and devastating disappointments.
Finally, the book narrows on Johnson’s first-person account as a rising planetary scientist. While she was still in college, she worked in mission control for a balloon-adventurer testing Mars technology and then held a formal NASA internship. She encounters Maria Zuber, the only other female scientist featured in the book and the only woman among 87 investigators on NASA’s Mars Global Surveyor mission. The MIT professor became Johnson’s PhD advisor. Their charming relationship becomes the special sauce for Johnson’s professional perseverance, a subtle flavour that cuts through the meaty personalities of the male luminaries around her.
Planetary science smashes together biology, geology, and rockets. A scientist myself, I found Johnson’s explanation of Mars science hard to follow at times. I Googled vellum, pyroclasts, teyphra and crinoids in one sitting. Johnson’s lyrical analogies help, but readers interested in the biophysical and chemical processes at play may have extra homework. Readers interested in the human saga will cruise right through.
This is a book about Mars science, yet its narrative holds relevance, and even lessons, for the unpredicted mission now facing the scientific community. The inevitable evolution of scientific thinking is hard to communicate to non-scientists but Mars science helps. According to Johnson, each Mars missions encapsulates “one of the most fundamental things about scientific discovery”, that “the truth can be a chimeric thing, that the collapse of an abiding belief is always just one flight, one finding, and one image away”.
Johnson provides a critical view of the late scientist and beloved science communicator, Carl Sagan, who during the 1975 Viking Mars mission promised turtle-like Martians. Then Viking’s on-board sensors suggested there was “not only no life on Mars but also why there could be no life”. Johnson articulates an unpopular yet not uncommon sentiment held by Sagan’s contemporaries: he was “irresponsible” when wielding hype.
The public’s high expectations for Martian life were not forged in the hearth of science fiction novels. Johnson describes how scientists across generations — not just Sagan — are partially responsible for society’s disappointment each time the curtain has been raised a little more on a barren planet. She convincingly insists discoveries still await but does not hang her hopes on present-day Mars microbes or aquifers. Her own science ultimately lands on an existential biological question: what does it mean to be alive in the universe?
Johnson’s chronicle of Mars science has a distinct voice, deeply poetic and fiercely female. She describes her first pregnancy and the professional sacrifices she has made as a mother. The most revealing passage centres on a small fern she finds on a school trip on top of a Hawaiian volcano, above the tree line. It’s the moment she becomes dedicated to planetary science “not (for) fame or glory, or a sense of adventure, but a chance to discover the smallest breath in the deepest night”, demonstrating that poetry flows from her pen and drives her ambition.
Johnson loves Mars for what it is, not for what it might be or what we could make of it. Perhaps this is the quintessential virtue of a mother. Hers is a wildly refreshing personal gaze, a female gaze, within a chronicle of famous historical gazes, including Galileo’s and Sagan’s. And while Johnson is not the face of extraterrestrial life detection, with Sirens of Mars, she clearly positions herself to become its voice.
Clare Fieseler is the Justice Sandra Day O’Connor Fellow at the Smithsonian Institution where she studies conservation biology and science diplomacy. Her forthcoming book No Boundaries: Inspiration and Advice from 25 Women Explorers and Scientists will be published by National Geographic Books in 2021.
