One of the foremost tasks of art has always been the creation of a demand which could be fully satisfied only later.
—Walter Benjamin, “The Work of Art in the
Age of Mechanical Reproduction”
At the end of 2000, Bill Hartmann’s answer to the question of Mars’s inner activity sits on an easel in the middle of his studio, a few blocks away from the University of Arizona, Tucson. A dark volcano climbs gently from a rusty plain. Behind it, the sky changes color. Near the horizon it is dusty red; toward the zenith it is a dark, bewitching blue, almost the blue of an Arizona evening. Here, though, the blue is a passing shade of twilight—by day the sky would be washed yellow by fine dust from the plain. Now, darkening, it is split by clouds of smoke from the mountain’s peak. The sun catches the clouds from beyond the horizon; an angrier light, hot and red, lends fire to them from below.
Hartmann has been studying Mars since Mariner 9 and he is one of the world’s undoubted experts on the age of the Martian surface. He’s also an experienced landscape photographer and an artist of talent and some modest fame (not to mention a writer and novelist as well). The common theme in his achievements is a love of landscape—earthly and unearthly. As a child he sketched and painted the world around him; in the evenings he looked through his telescope at other worlds. As a teenager in the 1950s he used his telescope to study and map the moon. Then he built plaster of Paris models of his favorite crater, Walter, to try to appreciate what it might be like from ground level, to turn a planetary object into a place. He wanted to answer the question that has driven him ever since: To see what it would be like to be there. The erupting volcano in his latest painting is an answer to that question; an answer based on his ever-strengthening belief that Mars is still an active planet.
It was this desire to get a better point of view that led to Hartmann’s first major contribution to science. After majoring in physics at Penn State, he moved to Tucson to take a masters in geology and a doctorate in astronomy as part of the new planetary science program that Gerard Kuiper was starting at the University of Arizona. Kuiper had struck upon a new way of seeing his moon and set Hartmann to work on it. The new technique was to take a high-resolution transparency of the full moon and project it, not onto a flat screen, but onto a white sphere. Features normally foreshortened spread themselves out over the surface of the sphere as it sloped away, and by wandering from side to side it was possible to look at the familiar face of the moon from new angles. Using this new unearthly perspective, Hartmann saw aspects of the surface never before appreciated. Most strikingly, Mare Orientale, an obscure dark patch forever on the limb of the moon as seen from Earth, was revealed as the center of a startling multi-ringed bull’s-eye of an impact basin, perhaps the most dramatic single feature the moon’s face has to offer.
Impacts went on to become a major theme in Hartmann’s work. In the 1980s he was one of the researchers responsible for the now widely accepted theory that the moon was actually formed in an impact—one to dwarf even the impact invoked to explain the Borealis basin. The idea is that as planetesimals accumulated to form planets in the very earliest days of the solar system, they produced not four inner planets, but five. The fifth planet was about the size of Mars and in an orbit that crossed the Earth’s. It and the Earth eventually collided. The planets’ cores merged; their mantles and crusts melted and mixed; and some of the ejecta was thrown out into space. Orbiting around the molten Earth this ejecta coalesced to form the moon. This theory has some nagging inconsistencies, but in general it explains well the ways in which moon rocks differ from rocks on Earth and the ways in which they are the same.
Bill Hartmann is not the first artist to include the face of the moon when he paints or photographs landscapes. Jan van Eyck’s detailed representations of the moon in a pair of sixteenth-century altarpieces mark a watershed in the realistic portrayal of the natural world. The American West, where the moon seems so oddly present, has seen much use of the same idea: Think of Ansel Adams’s Moon over Half Dome, or indeed of Moonrise, Hernandez, New Mexico, perhaps the best-known photographic landscape of the twentieth century. There, as in the van Eyck crucifixion, the moon offers a lifeless counterpoint to the crosses in the foreground. Hartmann is not an artist in that league, but when he includes the moon in one of his earthly landscapes he has the joy of knowing where it comes from, a subject he is happy to talk about with prospective purchasers. “It seems to me that people might like a landscape painting with a daylight moon by ‘the person who helped figure out the origin of the moon,’ ” he told me with a laugh when I visited his studio. “I figure this effect will kick in as soon as I die and it’s too late to do me any good.”
While taking his degrees, Hartmann spent little time on art. In the mid-1960s, though, when he was commissioned to write a textbook, he saw that including line drawings would make it much more interesting—textbooks were dry in those days and photo reproduction an expense academic publishers found easy to forgo. Still, he didn’t go out of his way to make his colleagues in the sciences aware that he painted planets as well as studied them, for fear they would look down their noses at him. “It was like being in the closet,” he says. In the 1970s he put together a popular book about the discoveries made through Mariner 9, called The New Mars. It includes a few paintings by others—the Czech artist and author Ludwig Pesek, Don Davis, who worked with the Hayden planetarium, and the great Chesley Bonestell, whose Life magazine pictures of astronomical scenes had adorned Hartmann’s walls when he was a boy—but none of his own.
Slowly, though, he started to out himself to his planetary-science colleagues. “I’d listen to a talk and do a painting and send a slide to the guy who’d given the talk.” After a while he began to see the slides turning up in further talks; not long after scientists started to suggest new topics for paintings. In 1981 he and Ron Miller, another author and artist, produced a book called The Traveler’s Guide to the Solar System featuring paintings of all the major planets and many of their moons, not to mention assorted asteroids and a comet or two. There are images produced by spacecraft in the book, too, but the paintings take pride of place. The pictures are scrupulously honest, trying to imagine nothing that cannot be backed up by appeal to the facts. At the same time they are gloriously dramatic. Jupiter and Saturn hang above the surfaces of their moons in implausible splendor, echoing but far surpassing the moon in the Earth’s sky. The great wall of Mare Orientale glows in glorious blue earthlight.
The Traveler’s Guide, revised and expanded in the 1990s as The Grand Tour, is probably the best-known showcase of realistic extra-terrestrial landscape art around. The genre is a small one; there are only about a dozen artists in it that any but the most die-hard aficionado could name. Kim Poor’s Novagraphics gallery in Tucson is the only commercial outlet devoted to the stuff (and even there, most of the money comes from signed Apollo memorabilia). It may seem strange that this profession should persist at all in an age when the planets have been visited and photographed in close-up. But it is precisely because of planetary exploration that the paintings are both possible and popular. The artists, while working in a strictly realist idiom, can still create landscape in a way that the controllers of a spacecraft camera cannot. As Kim Poor says, “Artists go where engineers fear to tread.” Reproduced at planetariums as posters and in books and magazines, the aesthetic these artists are committed to still has a powerful influence on the way that the solar system is seen.
In some ways the art has an oddly old-fashioned feel. It is art that prizes representation very highly, which minimizes the role of brushwork and gesture. It has a close relationship to technical illustration and prizes the mimetic over the expressive. It is not that the artists are blind to other approaches. In Hartmann’s studio there’s a striking work in progress that he began at Artist’s Point, the place where Thomas Moran painted The Grand Canyon of the Yellowstone in the 1890s. In tribute to Moran—and Moran’s inspiration, J. M. W. Turner—the picture has a strong sense of movement and expression, of light as something solid. But such effects are largely missing from Hartmann’s astronomical paintings, as from those of his peers.
Richard Poss, who teaches at the University of Arizona, argues that today’s astronomical art is usefully understood in the context of the school of American landscape art that Moran was extending and moving away from, the Hudson River School of Thomas Cole and Frederic Church. The Hudson River School, as the critic Robert Hughes has written, played a key role in turning America from territory to landscape, from a thing of exploitation to a thing of contemplation. Their landscapes celebrated the expansiveness of the American scene with a clarity of vision that offered detail and drama. The specific topography was not necessarily important: The thing that mattered was communicating the possibility of a new world and bringing its brightness directly to the eye, which is just what Hartmann and his peers try to do.
Unlike Turner and the landscape artists who followed him, for whom expressing the experience of the landscape became so important, the astronomical artists choose largely to limit themselves to what landscapes should look like, rather than how they might feel. A feeling would be speculative; the look can be ascertained with some degree of accuracy. And just as the artist is to some extent excluded from the work, so, often, is the human form. Perhaps the most influential astronomical paintings of all time were Chesley Bonestell’s first portfolio of Saturn as seen from its various moons, published in Life magazine in the 1940s. In these amazing pictures there is simply no place for people. In a way this comes as no surprise. Bonestell had worked as an architect (playing a role in the design of both the Chrysler Building and the Golden Gate Bridge), and as a matte artist in Hollywood, painting backgrounds that would trick the eye into accepting as real places the camera could not actually capture, such as the palatial Xanadu he created for Orson Welles’s Citizen Kane. Like an architect, the matte painter creates a world for others to inhabit.
Bonestell soon found himself putting people in the pictures, though, as when he collaborated with Wernher von Braun to illustrate the human exploration of Mars for the readers of Collier’s magazine. As a commercial project, planetary art with people in it has a much larger market than pure landscape. The subject is changed from observation to travel and the painting becomes a piece of science fiction, rather than astronomy. While Hartmann often does without people completely (there are hardly any people in The Grand Tour, even in the pictures of Earth), he sometimes adds them to an otherwise finished painting. Sometimes these people—whom Hartmann normally paints in blue space suits, in part because “our eyes on Mars will be starved of blue”—help the composition. Sometimes, I suspect, they are there for the simple reason that Hartmann wishes he could be. And sometimes they are the result of a commercial calculation. There are private fans and corporate sponsors—big aerospace companies and NASA, for the most part—who make such science fiction worth painting.
Some sensibilities see the frequently commercial transition to science fiction as a diminishment; others see it as a virtue. It certainly adds to the art’s potential, allowing it to express a wider range of ideas. Poss sees the way today’s astronomical artists use people as an intriguing ideological break with the legacy of the Hudson River School. Thomas Cole and his cohorts were engaged in a reactionary project. They recorded the Hudson and the wildernesses to the west not as they were at the time, but as they had been before the beginnings of industrialization—the process that provided their patrons’ wealth. While man appears in their wilderness images, he is either a lone icon—Daniel Boone by the stream—or a shadowy axe man, waiting to fell the forest. In today’s art of planetary landscapes, the presence of people is, by contrast, generally positive. They are studying the landscape with awe and respect; they are building a future. Such paintings combine a romantic respect for nature with a technophilic optimism. They are allegories of progress that embody a rare and pleasing belief that the good can come to, rather than just from, the beautiful.
Mars lends itself to such treatment particularly well. In large part this reflects the fact that Mars is a potential site of manned exploration; people on Mars have a far more immediate iconic significance than people on obscure bits of ice at the far end of the solar system. Another factor may be that the focus on the sky that is often the hallmark of purely astronomical art—such as the Bonestells of Saturn from its moons—doesn’t really work on Mars, with its hazy atmosphere and frankly disappointing moons. Many more artists have painted Mars from its moons than have painted the moons from Mars, because from the moons the view is quite superb: Mars broad and gaudy in the vacuum-clear sky.*
The typical Mars image is of spacesuited explorers—normally a team of them—in a somewhat Arizona-like landscape, often with dust clouds in the distance, like the storm clouds of the Hudson Valley. The explorers are in some situation of discovery; they are finding a geological oddity, or a fossil, or a spacecraft from a bygone era, such as ours. Normally it is something meaningful, occasionally it is something allegorical. In The Key, by Pat Rawlings, a globe of the Earth lies nestled in the Martian sand. There is always a sense of temporal tension, of the land and its secrets being old and the explorers new. In The Key the continents on the globe are arranged as they were 250 million years ago, and yet this ancient artifact is covered by just a little windblown dust.
Mars, these images say, is old and changeless, but made new again by those who see it for the first time. Perhaps the best-known painting of such a discovery is First Light, also by Pat Rawlings, in which the object of discovery is Mars itself. An astronaut is silhouetted at the edge of a canyon, setting up an anemometer, while a companion lowers himself down the cliff face; behind them the sun is rising and the mist in the void below them captures the shadows of the canyon’s far wall. The cliff in the foreground and the sky far from the sun are dark as night, the mists glow silver, the sunrise golden. If there’s an antecedent to this image it’s not among the precise renditions of Cole and Church. It is Caspar David Friedrich’s romantic masterpiece Wanderer Above the Sea of Mist. But whereas in Friedrich’s painting the backlit figure looking out over the bright mountain landscape is a central intrusion, blocking our view as he contemplates nature, in Rawlings’s piece the two figures are smaller and off-center. They are within the landscape, not above it. Only the standing figure’s anemometer mast breaks the horizon, its horizontal vanes offering a faint evocation of some alpine Calgary. Rather than simply looking at the sublime, they are studying it, measuring it, lowering themselves into it. Friedrich’s rambler has arrived; Rawlings’s astronauts have a world still to discover.
One purpose of such figures in landscapes is to offer a sense of scale. On Mars, though, this rarely works. The most spectacular attributes of Mars—the vast canyons, basins, and mountains—cannot be captured because they are simply too big. The canyon lands of First Light look very modest by Martian standards, probably a minor part of the Noctis Labyrinthus system; the detail that can be seen on the far side shows that they have nothing like the scale of Valles Marineris, though many who look at the picture doubtless think that is what it represents. As for the mountains . . . “Everyone asks, ‘Did you do a painting of Olympus Mons?’ ” says Hartmann with a laugh. “Well, you can’t. If you back off far enough to see it you’re too far away. It’s the size of Missouri. It’s like a picture of England as seen from France. You can’t paint the Rocky Mountains in one painting.” The artist’s dilemma in trying to capture planetary phenomena on a personal scale is brilliantly captured in “The Difficulties Involved in Photographing Nix Olympica,” a short story by the British author Brian Aldiss. Its focus is not on the photographer himself, but on the acute mixture of alienation and agoraphobia felt by the companion he sends off into the barren landscape in a vain attempt to add some sense of scale to the all but imperceptible rise of the mountain.
Aldiss realized that the most fruitful approach to the Martian landscape would not be to try to understand it on the human scale, but rather to contrast it to the human experience. Perhaps the first truly successful use of the planet to this end was in Watchmen, an ambitious and accomplished graphic novel written by Alan Moore, drawn by Dave Gibbons, and published, like Aldiss’s story, in the mid-1980s. One of the principal characters in Watchmen is Jon, a once human superhero whose vast powers over time, space, and the structure of matter have made relating to humanity hard for him; reasonably early on in the action he removes himself from the Earth. Gibbons, looking for inspiration, came across The Traveler’s Guide in a library and was captivated by its chapter on Mars. He loved the realistic treatment it offered of an alien, inhuman world; he was also struck by some strange synchronicities. Most extraordinary was seeing a picture of the smiley face in Galle crater; extraordinary because a smiley face (with a splash of blood across it) was a key part of the graphic novel’s recurring imagery. He enthused to Moore about the possibilities these Martian landscapes offered. As a result the novel’s ninth installment sees Jon and his one-time lover, Laurie, floating over the planet’s best-known landmarks as they talk about the most intimate details of Laurie’s past and the nuclear apocalypse threatening the Earth. Godlike Jon appreciates the vast scale and age of the landscape below them in ways that no human could—and attaches little significance to Laurie’s memories or to the end of life on earth.
The failure to find any trace of life on Mars in the 1970s was as harsh a blow to science fiction as it was to science. It had almost always been the Martians, rather than their planet, on which the fiction had focused. From the mid-1970s to the mid-1980s there was remarkably little new science fiction about Mars. Inspired by The Traveler’s Guide, Moore found a way to reclaim what had been lost by giving significance to the planet itself, rather than its inhabitants. Mars offered him a contrast to the pettiness of Earth as sharp as the divide between one panel and the next. It provided a place of timelessness to frame the sharp cuts between different events in Laurie’s memory. It provided a way to talk about the absence of life as something other than death. Life, Jon tells Laurie, “is a highly overrated phenomenon. Mars gets along perfectly well without so much as a microorganism. See: There’s the South Pole beneath us now. No life. No life at all, but giant steps, ninety feet high, scoured by dust and wind into a constantly changing topographical map, flowing and shifting round the pole in ripples ten thousand years wide. Tell me—would it be greatly improved by an oil pipeline?”
Moore made memorable use of Mars, and Gibbons got the opportunity to create his own renditions of the landscapes he had discovered in Hartmann’s and Miller’s book. But he also found himself having to try things Hartmann and Miller had wisely avoided. Moore devoted a page of the script from which Gibbons worked to building up Olympus Mons, “A sizeable mountain, very far away . . . The sizeable mountain is now quite a large mountain, still very far away . . . The mountain is now a bloody enormous mountain, and it’s still a long way away . . . Olympus Mons, now completely filling the background. It is still some distance away. We are starting to understand how incredibly huge it really is.” Gibbons took his best shot at turning these instructions into images for the readers, but it defeated him, as it had to. Comic books are drawn at Laurie’s scale, not Jon’s.
The volcano now standing on the easel in Hartmann’s studio is a much more manageable thing—perhaps the size of Etna, or maybe Ararat, and lower in profile. There are no people in the picture—yet—but there’s a sort of life. The planet itself is active; its surface is renewing itself. Ten years ago, with or without people in the frame, this would have been widely seen as a fiction. Mars was ancient and inactive. Today, Hartmann is convinced that it’s on the other side of the divide: that the eruption counts as realistic astronomical art, because the surface of Mars is still being renewed by volcanism.
Hartmann’s approach to dating the surface of Mars works by comparing it with the moon. On the moon, it’s possible to translate the ages derived from crater counting directly to absolute age measurements, since the Apollo missions brought back rocks that could be dated through the analysis of radioactive decays. If Mars had been hit by objects similar to those that hit the moon, and at the same rate, then the rules used for translating lunar crater counts into absolute ages could be applied to Mars. And even if the rate at which Mars was hit was different, a similar calculation could still be made, as long as the difference in cratering rates was taken into account. Thus if Mars was hit twice as often as the moon, a Martian surface with the same crater count as a lunar surface would be half the age of that corresponding surface, because craters on Mars accumulated twice as quickly. To stir up audiences at scientific meetings Hartmann sometimes calls the ratio between the cratering rate on Mars and on the moon “the most important number in the solar system” because it is so crucial to dating the Martian surface. And it lives up to its importance by being an infuriatingly hard number to ascertain.
Mars is closer to the asteroid belt than the moon is, which means you might expect it to get hit by asteroids more often. Because it’s farther from the sun, though, it’s less likely to be hit by a comet, and comets cause craters too. Mars moves more slowly than the moon and slower impacts mean smaller craters. But since it is larger than the moon, its gravity will speed an impactor up more as it gets closer. Having worked his way through all these issues, in 1977 Hartmann came to the conclusion that the rate at which craters formed on Mars was about twice that at which they formed on the moon. That allowed him to put rough dates to the three Martian geological periods. The Noachian–Hesperian boundary was put at three and a half billion years ago. The Amazonian period began 1.8 billion years ago and the surface of Olympus Mons, as fresh as anything on the planet, was just two hundred million years old.
To earthly geologists this made most of Mars terribly old: In 1977 everything that happened before the beginning of the Earth’s Cambrian era, about 540 million years ago—the point when animals developed shells that could be fossilized—was considered profoundly ancient. But among planetary scientists, used to a moon where most things had happened more than three billion years ago, Hartmann’s chronology soon came to be known for the youthfulness it conferred on Mars. Gerhard Neukum and Donald Wise, working with different assumptions about the best way of measuring the rate of cratering on the moon, suggested that craters of a given size were actually produced on Mars at only a quarter of the rate they were produced on the moon. Given these assumptions, Martian history looked very different: In the Neukum and Wise model, the Hesperian period ended before it had even begun in the Hartmann chronology. Almost all the volcanic activity Mars had ever seen was held to have taken place in the first billion years of its existence; by the time the solar system was half its current age, all Mars’s volcanoes had shut down. Mars today was cold and dead.
For most of the 1980s the two approaches were in a standoff, though Neukum did modify his estimates a little. But evidence from a completely different field was to begin tilting things toward Hartmann’s views. In the early 1980s it started to become apparent that there were already some samples of Mars available for analysis on Earth. This evidence came from eight unusual meteorites, known as the SNCs. The SNC meteorites were made of basalt, which argued that they had been knocked off a body that had a chemically distinct crust and mantle (basalt is what you get from melting and distilling the rocks of a mantle). At least one of the larger asteroids—Vesta—seems to have basalt on its surface, but the SNC meteorites did not seem to come from Vesta. Nor did they come from the moon (though some basalt meteorites do). By the end of the 1970s, Mars seemed, in the careful words of Mike Carr at the USGS, the “least improbable” source. Then researchers looking at shocked glass within one of the rocks found that it held traces of an atmosphere, in the form of unreactive (“noble”) gases; and the mix of noble gases was more or less identical to the mix measured by the Viking landers. The meteorites had come from Mars.
Despite this evidence it took some time for the SNC meteorites to be taken seriously as evidence for what Mars might be like. Part of the problem was finding a plausible means by which they could have been launched from the planet’s surface. This was sorted out a few years later, when it was argued that the atmospheric shock wave following a larger meteorite impact could boost some of the impact ejecta into orbit. By the late 1980s, then, the SNC rocks were thoroughly accepted as far-flung bits of Mars. Their chemistry provided proof that Mars had differentiated into a core, mantle, and crust at the very beginning of its history, thus ruling out the “late core formation” hypothesis for the great north-south dichotomy. Radiological dating showed that they were young. The Nakhlites (named after the first stone of the class to be discovered, the Nakhla meteorite that fell in Egypt in 1911) had cooled from their molten form about 1.3 billion years ago. The Shergottites, named after the meteorite that fell near Shergotty, in India, in 1865 were about 170 million years old. So Mars was still producing basaltic lavas relatively recently.
Quite how recently Hartmann was not able to say until the late 1990s, when MOC, the high-powered camera on MGS, started sending back images of the planet’s surface. Hartmann concentrated on looking at the new images of areas that were already known to be comparatively young. The areas he was looking at had few large craters (that’s how they were known to be young); the new images showed them as being nearly devoid of small craters, too. That pulled the age limits ever more firmly toward the present. For some surfaces in Elysium and Amazonis—and high on the slopes of Olympus Mons—Hartmann came up with ages of between ten million and a hundred million years. Alfred McEwen, at the University of Arizona, looked at the pictures and found what seemed to be exquisitely fresh textures on a great flood of lava that covers southern Elysium and much of Amazonis. All sorts of fine details were visible; again, the craters suggested an age of as little as ten million years.
There are complications. In some places, it appears that a layer of rock that lay above some of these lavas has been eroded away. If that layer protected the rock below from cratering, the lava flows might be older than their fresh face suggests. But, Hartmann asks, can this argument really apply to all the freshest surfaces—which total about four million square miles. Can it apply to the utterly uncratered areas on the high flanks of Olympus? Better, he suggests, to avoid the special pleading and go with what the landscape seems to be saying: that in some places Mars, though ancient, is still capable of renewing itself.
* There is one very striking piece of art that takes one of the moons as its subject, but it is a photograph, not a painting. Ed Strickland is a Mars enthusiast who, but for graduate work burn-out, would have become some sort of planetary scientist, and who now works as a computer consultant in Texas. Starting with an image of Phobos taken by the MGS MOC, he screened out the sunlit part of the moon and enhanced the brightness and contrast on what was left. The ghostly result is the face of Phobos lit by Mars-shine. Quite why this is so impressive I am not sure: If you saw it without knowing what it was you’d just think it was a rather poor picture. Perhaps it is the fact that this is the only picture I have ever seen in which Mars is actually doing something—taking an active role in the universe. Perhaps it is just the fact that it was a neat thing to think of doing.