THERE’S A TINY print of one of the Mariner 4 images on the wall of my office. I have it upside down and tilted, ever so slightly, to reflect true north. The picture is black and white, bordered with hatches. In the image, the sun shines down at an angle over the ragged Martian surface. It lights half the rim of each crater, then shadows the opposite side. I affixed it to the wall next to my desk because it speaks volumes about the challenge of doing science on other planets. The ground is visible in that grainy image, but it’s blanched of color, distant and barren. I know that it’s Mars, the vast terrain south of Amazonis Planitia, but at the same time, it’s nothing like the Mars I know.
I have it hanging next to a copy of the 1962 Mars map used to design the Mariner 4 mission. It was drawn up at the behest of the U.S. Air Force, and it’s the same map that hung throughout the corridors of JPL a half century ago. The contrast couldn’t be more striking. Mars is smooth, awash in creamy pastels of peach and gray. Tracts of bright and dark areas are graced with names that curve and slant to fit the landscape: Thaumasia arcs over Solis Lacus; Mare Hadriaticum is horseshoed around the bowl of Hellas. Above and below the rectangular Mercator projection of the planet are smaller views of the curved Martian globe, six in all, floating against the blackness of space like a collection of holiday ornaments. Whereas the Mariner image is a set of static pixels, lingering alone, the planning map is a representation of a world. It’s hypnotic, suffused with meaning. Every position, every orientation, every shape, every shading—each indelibly captures a human interpretation of an observation.
I know what it’s like to make a map. I learned to survey in the eastern Sierra as part of a winter field camp out in the no-man’s-land between Death Valley and the Mojave Desert, where the roads cut like scratches into the bleached and bending landscape. It was a swath of the Earth that no one really needed to know anything about, almost by definition. But that was the point: We were there for the challenge. The goal was to reduce the million-year-old pushing and pulling across a wild expanse of Earth’s crust into a set of neat lines, etched on flapping pieces of map paper.
Out in the death-dry mountains, I slept in a small yellow tent, rising with the sun each morning. I’d throw on a thick old sweatshirt, eat breakfast from a bent metal cup, grab my Brunton compass, and meet the other graduate students by the trucks. The air was clear and cold and still, making things that were far seem close. We’d drive into the distance and spend the day tramping around the desert washes and ancient riverbeds, ascending the rock slopes.
I was learning from one of the greats—a tectonicist named Clark Burchfiel, who had a gap-toothed smile and learned to play football back in the time of leather helmets. He’d recognized the pull-apart origin of Death Valley some forty years earlier. He trained us to stick closely to outcrops, places we could measure a strike and dip in the folded and faulted rock. I used my rock hammer to break off small chunks of the outcrop to inspect the minerals, swinging it over my head to get enough torque, then recoiling as it made a sound like the smashing of teeth. I marked the GPS coordinates where molten quartz had once squirted through sills. I traced where the brittle, jagged rocks ceded to pebbled pavement, then to alluvium.
One evening, Clark tossed me a rock. The minerals seemed to have ripped, lacerated in the darkness of our planet’s twisting and sheering. “This rock has seen the face of God,” Clark whispered, seemingly to himself. As I stared at it, I realized I’d spent my life walking on top of the thinnest of eggshells, oblivious to the heat and the pressure beneath me, oblivious to the magnitude of forces and depths of the physical world. Yet as hard as I searched for fault lines and intrusions on my own, I passed my days in the field wandering around feeling lost. The desert was unyielding and silent. There were great boulders perched upon ledges, and sometimes, with no one around, I’d push one with all my might until it would trundle off the peak, just to hear it crash down hundreds of meters below me, to watch it break open.
I’d work from dawn until dusk, struggling to make sense of my measurements, thinking that these mountains were no place for a beginner. Then the sun would set. I would turn in as soon as the fire died, as darkness settled over the Mojave. I’d switch on my headlamp, illuminating my little yellow dome against the cold playa. I’d lugged a dozen books with me. They were stacked in piles around the inside of the threadbare tent, which held next to nothing else. I read West with the Night by the pilot Beryl Markham, who flew passengers around Kenya in the 1930s for a shilling a mile. Ernest Hemingway called the book “bloody wonderful” in a letter to a friend: “This girl…can write rings around all of us.” I read Michael Ondaatje’s The English Patient, and like the protagonist Ladislaus de Almásy, who brought Herodotus’s Histories into the desert, I began taping maps and sketches into the pages of my books. Cather, Dostoyevsky, Dillard, Blake, Coetzee, Stendhal. I searched them like a nautical almanac. All I wanted was to find some solid points, some method to triangulate, some way to pattern a sense of human understanding onto the vast physical world around me, a world marked by human absence.
Soon, though, I began to realize the Granite Mountains weren’t as intensely empty as they seemed. When I’d first gazed into the Mojave, everything seemed muted. All the color had been drained, sipped away by the parched air. The plants were a whitish khaki green, like fistfuls of dried herbs. I had the urge to spit on them, thinking it was the least I could do, a small act of kindness. But after a while, my senses started to adjust. The sagebrush began to look like splashes, almost like raindrops hitting a lake. I started to see the life all around me—in the spine-waisted ants and blister beetles, even in the dark varnish of the desert rocks, a sheen potentially linked to microscopic ecosystems.
One day, I traced where a fossil layer had vanished, the erasure of creatures that had dominated the world for a twinkling of history. Then another afternoon I noticed similar shapes several kilometers away, in similar rock. I followed how the belts of rock plunged into the earth, then scanned the horizon, trying to envision where they might reappear. I was connecting the dots through the depths below, the bending masses, hundreds of meters beneath my boots.
The effect this had on me called to mind another of the books in my tent. I’d read about Antoine de Saint-Exupéry and how his plane was forced down in the Sahara one night. Helpless until day dawned, he fell asleep on a hillock of sand, then awoke suddenly on his back, “face to face with a hatchery of stars.” He was “seized with vertigo,” flung forth as if he were falling, as if the sky were a sea and he was diving headlong into it. The day on the ridge felt like that, the convex suddenly concave. I had a visceral sense of the world popping from two dimensions into three, of seeing a landscape in a way I’d never viewed it before.
With a little data and a little imagination, I was beginning to grasp how disparate observable strands could be woven into a system. And once the terrain began to make sense, all I wanted was to get to the next ridge, to fit it into my map. It was as if I could peer into the unseen ground. I didn’t want mere pieces of that mighty system, some surficial understanding. I wanted the coherent whole.
THE MARS PLANNING map that hangs in my office is full of cartographic detail—a panoply of features and names. But if you step back a bit, what first catches the eye is the light and the shadow. All across the map are hubs and spokes: an extensive interconnected system of perfectly straight lines. The crisscrossing patterns are the color of smoke. They’re not black, not unambiguous, but they are impossible to miss. They decorate the surface like a Victorian lace collar.
The lines date to the late 1800s, when they were first extensively recorded by Giovanni Schiaparelli, an astronomer in Milan who would forever change our vision of the planet. There had been much talk of Mars in the summer of 1877 as it swung particularly close to the Earth. An American astronomer had just discovered two moons through the great glass of a sixty-six-centimeter telescope at the U.S. Naval Observatory in Foggy Bottom. The lens of Schiaparelli’s telescope was much smaller, only twenty-one centimeters, but it was made out of high-quality glass, so he decided to see whether his instrument might also be suitable for observing planets. He climbed to the rooftop of the Brera Palace. A terrible storm had passed through, and he was struggling with the conditions, unable to resolve double stars in the windy, cold air. At just before 10 P.M., with one eye to the telescope, the other on his notebook, he made his first ever sketch of Mars: a circle near the book’s binding, a small white space denoting the polar cap, an apron of shading descending down from its edge, and, finally, a distinct round spot within a crescent of darkness. He noted in his observations that he couldn’t find the feature on an existing British map of Mars, considered the most accurate in the world. Puzzling. But then again, the air was not good.
Schiaparelli observed Mars the next night, and the night after that. The more he observed the planet, the more he was confused by the British map, which looked like two cartoon hands of dark terrain rising up from the equator. The dark areas were designated as seas, and the light areas continents. But nowhere among Kepler Land, Dawes Ocean, Herschel Continent, or the De La Rue Sea were shadings that actually matched the ones Schiaparelli saw. In fact, none of the maps of Mars seemed to bear any resemblance to the planet he saw through his telescope.
Given the wobbling atmosphere, Schiaparelli had to work fast, recording the image he saw before the vision of it faded. But he utilized a tool that few of the other mappers of Mars had: a tiny micrometer. He affixed the miniature contraption, which he’d learned to wield in Russia, to the eyepiece of his telescope. This helped him to locate several dozen points of longitude and latitude; he could then use these to quickly orient himself. Schiaparelli’s preternaturally sharp vision and this dedication to form resulted in a breathtakingly specific new map of the planet.
During those nights up on the rooftop observing Mars, Schiaparelli noticed curious features crisscrossing the planet’s surface, connecting dark patches—lines that would entrance and bedevil scientists for decades. He interpreted each dark patch to be a sea, “the saltier the water, the darker it appears.” He conjectured that the lines linking them were waterways. In time, he identified dozens of these “canali.” They always originated in a dark patch and terminated in another dark patch or another one of the canali, never in the middle of a landmass. In some cases, canali even appeared to split, changing rapidly into two parallel canals, closely spaced.
Within a few years, a French astronomer named Camille Flammarion seized on Schiaparelli’s maps and began interpreting them in the most optimistic light. In Italian, the word simply meant “channels.” Schiaparelli, who had trained in civil architecture and hydraulic engineering, thought that the features might be straits, like the English Channel or Mozambique Channel. But the word rushed into the wider world as “canals,” with everything that implied.
In La Planète Mars et ses Conditions d’Habitabilité, Flammarion noted how the “canals” didn’t meander like streams and rivers. In fact, the canals on the maps seemed oddly geometric. Were they public works? Across the face of the Earth, technology was manifesting itself in new ways. The Erie Canal, dubbed the Eighth Wonder of the World, was completed in 1825 and twice enlarged in the second half of the nineteenth century. France had been heavily involved in the creation of the Suez Canal, a maritime shortcut around Africa that opened in 1869. In 1881, the French also commenced work in Panama on a new passage to link the Atlantic with the Pacific. Flammarion analyzed the canals in the context of other observations and concluded in a massive compendium of all the sketches of the planet made through 1892 that “the habitation of Mars by a race superior to ours seems…very probable.” What else could explain the scale and regularity of the Martian canals?
It was the heir of a textile fortune who brought the canals to America and who would become their loudest and most prominent proponent. Percival Lowell had grown up in a grand mansion on Heath Street in Brookline, a Boston suburb. The house was nicknamed “Sevenels,” for the seven Lowells living there. Lowell’s brother would become a president of Harvard and one of his sisters a famous poet. Like his siblings, Lowell had access to a vast fortune. Upon graduating from Harvard, where he studied mathematics and dabbled in astronomy, he left on a customary grand tour and later spent several years traipsing through the Far East on various cultural and diplomatic missions. He was a self-proclaimed “man of moods,” one moment jocular, holding court among friends in his piazza, the next somber, alone, chain-smoking cigars. He liked tennis and walking, but not golf, not motoring. He owned one of the fastest polo ponies in America. He had tremendous personal magnetism and typically struck others as boyish and eager, though he was a hermit at heart.
Upon Lowell’s return in 1893, his aunt Mary presented him with a copy of a La Planète Mars et ses Conditions d’Habitabilité as a Christmas gift. Fluent in French, Lowell devoured it, electrified by the Schiaparellian network that Flammarion had interpreted as a series of waterways flanked with vegetation, carved deep into the surface to irrigate the land. The scope of the excavations was simply dazzling. There was tangible evidence of a civilization at hand. What could this be if not the biggest discovery ever made, if not a natural extension of the Copernican Revolution? Inside the book, Lowell scrawled, “Hurry!” The family motto was occasionem cognosce—“recognize opportunity”—something Lowell had become quite good at. He knew that in just a few months Mars would swing into opposition—when Mars and the sun aligned on opposite sides of the Earth. It would be Mars’s closest approach to our planet in fifteen years, and he wasn’t going to miss it.
In January, he met with a rugged young astronomer named William Pickering. Pickering had observed the linear features on Mars himself, reporting on them in an 1890 article in The Sidereal Messenger. He had also just returned from a remote outpost of the Harvard College Observatory in Peru, where he had developed his “Standard Scale” for rating astronomical vantage points. Pickering convinced Lowell that optimal viewing conditions could be found in the Arizona Territory. Smog and light pollution, by-products of industrialization and urbanization, were becoming major problems, so Lowell quickly set out to build an observatory “far from the smoke of men.” He decided on a high mesa at Flagstaff, a place where the atmosphere was steady and the night was cloaked in deep darkness. As Lowell insisted, “the best procurable air.”
Pickering designed a prefabricated dome that was shipped west by rail. Ground was broken that April, and the first observations of Mars were made in May. Not lacking for funds, Lowell’s Arizona outpost soon acquired a beautifully crafted sixty-centimeter refractor from Alvan Clark and Sons in Cambridge, Massachusetts, the leading optical manufacturer of the day. Alongside the telescope Lowell affixed a ladder assembly, atop which he set a kitchen chair. From his solitary perch, “but one watcher, alone on a hilltop with the dawn,” he scrutinized the planet through his state-of-the-art lens, sketching elaborate maps of the Martian canals, rendering them as perfectly distinct lines. Confident in his exceptional optics and eyesight, from an observation post reputed to be as good as our planet could provide, he identified dozens more canals than Giovanni Schiaparelli ever had.
Lowell patiently mapped the entire planet, including even the dark patches of the surface that had long been understood to be oceans. The canals were everywhere, even there. Lowell conjectured that he was not looking at a planet like Earth, awash in salt water, but rather at a world that had lost its seas, a world where the rain had stopped. Thus the need for a global network capable of pumping what precious water there was from the melting polar snows toward the equator each spring, giving rise to dark patches of vegetation. “If…the planet possesses inhabitants, there is but one course open to them in order to support life. Irrigation, and upon as vast a scale as possible, must be the all-engrossing Martian pursuit.” And since the canals were Mars-wide, and since there were no visible boundaries between regions or nations, Lowell reasoned that the planet had probably reached a kind of geopolitical end state where a group of benevolent oligarchs had come to direct the social order.
Whatever the likelihood of his political speculation, Lowell’s telescopic evidence struck the world as wildly exciting news. He didn’t have an advanced degree, but neither did many prominent astronomers at the time. There wasn’t all that much to learn in graduate school, because there wasn’t all that much to teach. Lowell courted the scientific journals and newspapers, and copies of his book Mars flew from the shelves. With its publication, much of the literate world was persuaded that proof of intelligent life had been discovered on the Red Planet. In English, French, and German, he addressed large crowds in North America, Paris, and Berlin. A “brave and brilliant début for the new science,” heralded the Boston Evening Transcript. The public’s fervor exploded as professionals and amateurs alike crowded in to hear Lowell’s talks and raced to purchase telescopes.
But Lowell had just begun. He soon started to construct a narrative for Mars’s history, a chronicle of events to account for how Mars came to be. It fit perfectly with his interpretation of planetary formation and the idea that planets would march toward an evolutionarily advanced state—both physically and biologically.
As an undergraduate at Harvard, Lowell had completed a thesis on the nebular hypothesis. The theory, first suggested on a somewhat intuitive basis by the philosopher Immanuel Kant during a foray into astronomy, and later by the celebrated French mathematical astronomer Pierre-Simon Laplace, held that rings of gas shed by the cooling, contracting sun condensed to form planets. Since entropy—the tendency toward disorder—was unidirectional, it would eventually lead to the senescence of the solar system, with the smaller planets dying first. So, from the time of their birth as molten masses, Lowell reasoned, the planets progressed through stages of development. Mars was clearly in a terrestrial stage where oceans had disappeared, but it was rapidly approaching a dead stage, an airless stage, the stage of Mercury and the stage “so sadly typified by our moon, a body now practically past possibility of change.”
The implications for our own planet were not lost on Lowell. Mars had advanced to a state that the Earth too would reach. Earth was still in a terraqueous phase—its sedimentary rocks laid down by water—but its fate was sealed: “The outcome is doubtless yet far off, but it is as fatalistically sure as that tomorrow’s Sun will rise, unless some other catastrophe anticipate the end,” Lowell wrote. “It is perhaps not pleasing to learn the manner of our death. But science is concerned with only the fact, and we have Mars to thank for its presentment.” Mars, he realized, was giving us a glimpse of our own future.
Lowell’s tour de force of popular science would hold sway over the public for years. Yet slowly, quietly, hints of doubt about the canal theory began to emerge, mostly in foreign periodicals. As early as 1894, a British solar astronomer had noticed that series of tiny sunspots tended to be drawn by the eye into lines and wondered whether the same thing might not be the case with small details on Mars. In 1903, he arranged a simple demonstration to challenge Lowell. He asked a group of schoolboys at the Royal Hospital School in Greenwich to copy a series of black-and-white drawings, placed at the front of the classroom, on which dark dots had been inscribed. The boys at the desks near the front mostly drew dots, but the boys at the back of the room drew lines: For them, the dots appeared to merge together. Lowell, never one to be dissuaded, countered that linear features would also appear as lines at great distances.
Taken aback by the challenge to what he viewed as his most important scientific legacy, Lowell turned to photography, hoping it would quiet the controversy. Because of its ability to build up an image of a faint object over time, photography was a tremendous asset in stellar astronomy. It had also revealed new moons around the outer planets, but pinpointing the dot of a distant object and resolving its features were very different challenges. Even under perfect atmospheric conditions, painfully slow film speeds meant that details in the images of Mars would show up blurred. Nevertheless, one of Lowell’s assistants designed a new planetary camera and took on the challenge. The photographs that emerged from the fixing solution in the Lowell Observatory’s darkroom after the 1905 opposition were half a centimeter across, hardly the kind of images that allowed for a comprehensive examination of minute terrestrial features, but Lowell still distributed them widely. He heralded them as foolproof evidence that the canals were real, and the president of the British Astronomical Association followed suit in 1906, proclaiming that the photographs proved the “objective reality of the canals.”
With much fanfare, Lowell announced that he would finance an expedition to the Andes to collect even better photographs of the planet in 1907. The much-hyped expedition was led by the well-known Amherst astronomer David Peck Todd, accompanied by his wife and Earl Slipher, a recent astronomy graduate from Indiana University. Amherst’s forty-five-centimeter refractor, weighing seven tons, was shipped from New York to Chile via the just-opened Panama Canal. It was set up in the open air in the nitrate-mining town of Alianza, some seventy kilometers inland from the old port city of Iquique. While Todd made visual observations of the usual kind, showing canals, the true master proved to be young Slipher. Even though he had only trained in Flagstaff for a few months, he quickly figured out the planetary camera and over the course of six weeks took nearly seven thousand photographs of Mars. The gelatin-emulsion glass plates, laced with silver salts, were crated up and returned to Flagstaff.
Reproductions of the images, grainy as they were, were published a few months later in The Century Magazine. Anticipating that readers were unlikely to be impressed, Lowell insisted on including the disclaimer that the photographs were three steps removed from their original negatives, having undergone photographic printing, halftoning, and press printing. Despite his reassurance to readers that on the original negatives “[the canals] are there, and the film refuses to report them other than they are,” they could hardly be seen.
Things continued to unravel. The same year, the celebrated British naturalist Alfred Russel Wallace, who independently conceived of the theory of natural selection, launched an attack on the concept based on his own research, arguing that Mars was likely too cold for liquid water and that a planetwide irrigation system was an absurdity. In 1909, the Greco-French astronomer Eugène Antoniadi, a longtime supporter of Lowell, published a map of Mars without any canals, practically the first such depiction in twenty-five years. Based on his own observations using the largest refractor in Europe, Antoniadi had changed his mind, concluding that only the “natural agencies of vegetation, water, cloud, and inevitable differences of colour in a desert region” were needed to account for the various phenomena on Mars. And all the while, the pioneering psychologists Sigmund Freud and Carl Jung were crisscrossing Europe and the United States, lecturing about the role of the unconscious, likely raising suspicions that observers might be seeing a vast network of canals on Mars because of an underlying desire that the canals existed. As Lowell’s evidence for an advanced society on Mars withered, his own discipline began to shift beneath his feet. Einstein’s theory of special relativity had been published, and space science swerved toward astrophysics, slowly relegating planetary science to a backwater it would not emerge from in Lowell’s lifetime.
Lowell continued to write and lecture, seeking to inspire students as he became more and more marginalized from the scientific mainstream. He died of a stroke in 1916. In a moving tribute, his secretary described him as “filled by the warmth of his fire; thrilled by his achievements, with eye single towards the discovery of ‘the light that shifts, the glare that drifts’—which is truth itself.”
AND YET THOSE lines that Schiaparelli had documented and that had so consumed Lowell continued to haunt Mars science. Every time the planet swung into one of its biennial oppositions, Lowell’s assistant Earl Slipher took photographs of Mars, one after another after another, from his early twenties until his eighties. Photographs from Flagstaff, Chile, South Africa. On countless nights, he stood and sat at the eyepiece of large telescopes, sometimes huddled in a plaid flannel overcoat, switching the plates, clicking the shutter, switching the plates, clicking the shutter, and so on as the hours passed.
Over the course of his lifetime, Slipher took over one hundred thousand images of Mars. In 1962 he arranged the best of them, sometimes alongside sketches he had made, into a volume he entitled The Photographic Story of Mars. “A vast collection of facsimiles and information has been amassed,” he wrote in the foreword. It was the compendium of his life’s work, and it became the basis of the planning map that hangs in my office, put together by the U.S. Air Force that same year.
In the early 1960s, of course, hardly anyone still believed that the lines on Mars were the handiwork of an intelligent society, but no one could say for sure what they were. Nearly seven decades after Lowell stumbled across Flammarion’s treatise, the former head of the Royal Astronomical Society of Canada wrote: “The so-called ‘canals’ of Mars…have been plotted in various forms by most observers of the planet…I can sum up the present situation by saying that there is general agreement on the reality of the canals, in other words that they are not illusions, but result from something on the Martian surface that produces the effects drawn by the visual observers and recorded on the photographs…” Samuel Glasstone affirmed, “There definitely appear to be a number of linear features on the surface of Mars,” in The Book of Mars, a NASA special report in 1968.
What were those eerily straight lines? Fissures, perhaps, caused by the drying and cracking of the Martian surface? Depressions? Radial streaks of material ejected from craters? It was difficult to explain why Mariner 4 didn’t see the spidery black webs, if indeed they were there. Did the flyby just miss them, with its handful of images only covering 1 percent of the planet? The improvement in image quality for Mariner 4 over telescopic photographs was so striking that the mission scientists had struggled to correlate them with any of the existing pictures of Mars. Perhaps the images were simply taken at too close a range? The mystery of the linear features was one of the reasons NASA decided to launch a second pair of flyby missions to Mars, in 1969. “Photography from the mission is expected to settle this point,” explained the NASA press team. In order to improve the coverage, far-encounter images were added to those taken up close during the flyby. A probe called Mariner 5 had been sent to Venus, so NASA named its next Mars missions Mariner 6 and 7.
By February of 1969, Mariner 6 was tucked inside a glistening nose cone at Cape Canaveral. On Valentine’s Day, the Mariner 6 ground crewmen began a routine test procedure. Unlike Mariner 4’s slimmed-down, simple rocket, the Atlas-Centaur rocket was enormous, towering over the cape like a skyscraper. Ten stories tall, it weighed 150 tons. It was far larger than NASA needed to get to Mars, but it was widely available, having been built in bulk to ferry NASA’s much heavier spacecraft to the moon.
Suddenly, the sound of buckling metal echoed across the launchpad, followed by the piercing wail of an evacuation siren. When the ground crewmen looked up, they couldn’t believe their eyes: The fixed solid launch vehicle, the unshakable, unyielding locomotive of a rocket that was designed to survive a blast into outer space, was collapsing under its own weight, its smooth metal skin rippling and folding like fabric, right in the middle of the launchpad.
Before they could respond, the top of the rocket had tilted to a twenty-degree angle, forming a kink in the cylinder. The balloon tank of the rocket relied on pressure to maintain its rigidity, but the design of the Atlas-Centaur had done away with all the internal structure, to save weight. The crewmen realized that the main valves must have somehow popped open, letting air rush out from fifteen-centimeter openings.
Time seemed to stop as the wires strung to the far side of the launch vehicle pulled taut, then popped. One of the workers rushed to secure the locking bolts as the booster sagged perilously toward the umbilical tower, then thudded onto the platform. Another worker wriggled his way up into the thrust section, trying desperately and finally succeeding in closing the valves, which prevented the crumpled rocket from crashing to the ground.
Those two members of the ground crew received Exceptional Bravery Medals from NASA for saving the Mariner 6 spacecraft, which was carefully extracted from the nose cone and transferred to another Atlas-Centaur. I wonder what it must have been like watching those straight edges warp, looking up at a rocket that only seconds earlier had been firm and solid, trying desperately to orient myself. How can a mountain lean, how can a palisade collapse, how can an Atlas-Centaur ripple? And yet Mariner 6 still launched on schedule, followed a month later by Mariner 7.
TWO DAYS BEFORE reaching Mars, the telephoto shutters on Mariner 6 opened, and the excitement began. As the spacecraft hurtled in from a hundred and fifty kilometers away, a long-studied linear feature was immediately spotted: the “canal” Coprates. It appeared on the terminator—the line that separates the illuminated day from the dark night—then arced across the disk of the planet and disappeared behind the edge. But by the time Mariner 7 pulled within twenty-four hours of its near encounter, shutters whirring, it seemed evident that Coprates was just a collection of dark dots aligned somewhat east to west, and not even straight.
It was the same for the images that followed, as Mariner 6 raced past the planet, and Mariner 7 followed with a ribbon of images over the South Pole. There was no geometric pattern on the surface. No doublings, no diagonals. Not even the soft angles of a crocheted blanket. It took only eight days for Mariner 6 and 7 to kill the linear features. The schoolboys had been right. For all that time, the lines we’d seen simply weren’t there.
So it was with the whole mission. As the probes collected images with their near- and wide-angle cameras, nothing was what it at first appeared. Mottled areas resolved into crater fields. A “lump” on the southeastern limb of the planet turned out to be a detached haze layer. The W-shaped clouds that had been observed for years were not clouds at all but rather a real surface feature.
Other boundaries once thought to be smooth and regular—along the edge of the south polar cap, between Mare Cimmerium and Aeolis—proved in fact to be ragged and broken. There were uncratered expanses, like in the depths of Hellas, a smooth, featureless terrain that must have been resurfaced somehow. There were fields of chaos—jumbled, blocky, broken terrain with no known counterpart on the Earth or the moon. There was structure to the atmosphere, layers and layers that hadn’t been detected before. There was a dramatic south polar cap, built with carbon dioxide ice. The mission even measured some warm temperatures along the equatorial latitudes, as warm as crisp fall days on Earth. Mars was not the Earth, but it was not the moon either. It was another world altogether. The whole mission, from the crumpling of the rocket to the data the spacecraft returned, seemed to underscore 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, one image, away.
TOGETHER, THE MARINER 6 and 7 near-encounter images covered 20 percent of the Martian surface. The probes discovered scores of new features, but the images had also undone much of what we thought we knew. We now lacked any semblance of a legitimate map. As the mission team struggled to fit all the new observations together, it became evident that NASA needed another Mars mission, a true mapping mission. And in 1971, Earth and Mars would align when Mars also happened to be at its closest approach to the sun. It would be a particularly favorable time—with Mars close in, there would be less distance for the spacecraft to travel. So in the run-up to the next launch window, NASA readied a pair of twin mappers: Mariner 8 and Mariner 9, identical spacecraft that would go into orbit instead of just flying by the planet. They would establish the Martian geoid, the reference grid from which all points could be identified: latitude, longitude, altitude. Mariner 8 would map the planet’s fixed features—the permanent ones, like deserts and craters—while Mariner 9 would map variable features, the ones that shifted with the seasons. It would do this by entering into a different orbit to image the same places at the same time of day as the Martian year progressed. Between the two missions, NASA hoped to eclipse all the historically crude and static representations of the planet’s surface.
As Mariner 8 and 9 were being fueled, enshrouded, and mated to their rockets, the Soviets readied three Mars missions of their own at the Baikonur Cosmodrome, vying with the Americans to place the first Martian satellite. Despite eight attempted missions, they had yet to achieve any success on Mars.
Mariner 8, the first of the five, blasted off on May 8, 1971, the very moment the launch window opened. Everything appeared to go smoothly for the first few minutes, but then the upper stage of the rocket began to oscillate and tumble. The payload was prematurely cut loose, and Mariner 8 fell through the dark sky. It splashed into the sea and continued falling, all the way down to the bottom of the ocean.
The next day, the Soviet mission Kosmos 419 launched, but the upper stage of its rocket also had trouble, failing to fire the second time, marooning the spacecraft in low Earth orbit for two days before reentering the Earth’s atmosphere. It turned out that an eight-digit code to fire the engine had accidentally been issued in reverse by a human operator; embarrassing, but easy to fix. Over the next couple of weeks, the Soviet missions Mars 2 and Mars 3 soared into space on Proton rockets.
Mariner 8’s failure had also been caused by something small, an integrated-circuit chip, no bigger than a sunflower seed. A faulty diode had likely failed to protect it from a voltage surge. The Mariner 9 engineers persevered through the rest of May after happening upon a second issue: a short in the propellant system. They hurriedly pulled the spacecraft down from the Centaur, fixed it, then reran a full set of tests. Finally, NASA got the spacecraft back on top of its rocket. On May 30, on a clear blue evening, Mariner 9 lifted into the sky, joining the race to make the first full map of Mars.