Between 1952 and 1954, the Nazi rocket scientist Wernher von Braun ran a popular series in Collier’s Weekly called “Man Will Conquer Space Soon!”, outlining a manifest-destiny approach to space, the moon, and Mars. The articles were prescient in their analysis of how we might colonize the stars, but what really brought the possibility of human spaceflight to life in the public consciousness were the illustrations: planets, rockets, human settlements. These were rendered by a trio of artists that included Chesley Bonestell, widely considered the father of what we’ve come to call space art. The genre soon bubbled over with breathless visual predictions of our ascent into outer space, wrought with glamor and a childlike wonder, like pulp-fiction covers for what the future was going to be.

People have been painting celestial bodies for thousands of years, but only after World War II, as space programs flourished, did the field evolve into a thriving subgenre, and an occupation in its own right; with new technology came a new lust for imagery. NASA , founded in 1958, has commissioned space art since its inception, and along with the European Space Agency it’s sponsored artists’ residencies over the years. “It could be argued that NASA owes its very existence to space artists,” Jon Ramer, president of the International Association of Astronomical Artists, told me in an email. The IAAA currently stands at 120 members worldwide, and serves as a sort of hub connecting the community.

NASA had a critical revelation early on: an astonishing discovery means nothing if the public only registers it as an abstraction. We can’t quite photograph black holes, for instance, though we’d very much like to. And most objects in space are either so faint or so distant that even the newest generation of telescopes can’t return images that do them aesthetic justice. Hence the value of artists, who can extrapolate scientific findings into fantastical craters and overlarge moons, their colors dark with science-fiction vibrancy.

We can trace the sparks for today’s space art as far back as Jules Verne, who published his novel Off on a Comet in 1877 with a painting by Paul Dominique Philippoteaux that imagined Saturn as more than just points of light in the sky. Before that, no one was depicting other planets as places you could stand on—places you could look up from rather than to. By the end of the nineteenth century, the astronomer Percival Lowell had begun to publish his series of illustrated books that reflected his claim that the lines he saw on Mars were artificial canals, the work of intelligent Martians. The public imagination quickened. In 1937, the French artist, author, and astronomer Lucien Rudaux published a book illustrated with what he believed the surfaces of other planets to look like. The book caught the attention of Bonestell, who had been working as a special effects artist in Hollywood. He began creating realistic paintings from the perspective of someone standing on the surface of the moon or Titan, publishing his work in Life in 1944. He became the most prominent name in the field, his vision bolstered by the work of a handful of iconic contemporaries such as Ludek Pesek, an artist and astronomer who’d also been inspired by Rudaux.

“Their work, painting places that were really out there—it started convincing people that these places are real,” Ramer told me by phone.

By the early sixties, NASA ’s administrator James Webb was enthusiastically recruiting the necessary talent for formation of a NASA fine-arts program. “An artistic record of this nation’s program of space exploration will have great value for future generations and may make a significant contribution to the history of American art,” he wrote in a 1963 press release announcing the arrival of the agency’s first commissioned drawings.

As the space race progressed, it was inevitable that space art became politicized. The Soviet Union got busy commissioning space art of its own, and the fifties and sixties were rife with propaganda posters (the Politburo being rather more aggressively nationalistic than NASA ). Thousands of space artworks have been produced in the decades since. Ramer says each NASA space center usually has an exhibition of selected works from its own program on display; they’re as popular and beloved today as they were when Webb conceived of them more than fifty years ago.

The prevailing styles today are “rock and ball”—the Bonestell-style planetary landscapes against a backdrop of distant planets and moon—and “swirly,” which refers to more impressionistic work that recalls Van Gogh’s Starry Night. But advances in technology brought advances in design: today you can find photorealistic space art, hardware art (paintings of tech, schematics, and so forth), even sculpture. There was no particular moment that heralded a shift in aesthetic from the postwar space paintings to the ones we have today. The colors gradually became fuller, brighter, with the vibrancy we associate with really good images of nebulas. The transition from overexposed yellows and olive greens came in part from improved telemetric images, but some of it can be attributed to visual trends in the culture; think how orange everything was in the seventies. For the most part, space art in 2017 continues to blend realism with just the right amount of creative flair, much as it did fifty years ago. What’s different now is how much more we know.

The idea of artistic license might seem anathema to astronomy, the epitome of a STEM field, but the factual restrictions imposed on space art are quite plastic. An assignment will come with both technical specifications and a kind of vacuum imposed by their limits. Space art, in other words, is uniquely defined by both hard data and imagination. At the outset of a new project, an artist might be told approximately how large a nebula is, or how far away a planet lives from its star. The artist can incorporate whatever data’s most recently come back from probes and orbiters; whether their assigned portion of Mars has mesas or dust devils or whether there maybe could be snow.

The artists who settle into this peculiar niche tend to arrive circuitously. They’re variously graphic designers, engineers, fine- or experimental-arts grads, self-taught hobbyists, or, in at least one case, former visual-text animators for Jimmy Neutron. They collaborate with science-fiction writers. They’ve sold paintings to renowned astronauts. Most of them render everything digitally or else begin the piece with acrylics and overlay more detail in Photoshop. The work can take months or less than a day.

In 2017, when NASA discovered potentially habitable planets orbiting the star TRAPPIST-1, Nature magazine assigned Robert Hurt to design their cover. Hurt knew the planets’ approximate sizes, and he’d read that they were close enough together to be tidally locked. This says something about their temperature gradient and symmetry, allowing for reasonable hypotheses about geology and atmosphere. Even so, most of the details that would make for a vivid illustration are unverifiable. “With most exoplanet work, what we actually know about how it looks can usually be written down on an index card,” Hurt told me. “What we don’t know is vast.” The planets seemed rocky, but some of them could have ice. Maybe there was an ocean world; maybe there were a few. To block out the artwork, he got a bunch of marbles and threw them all over his carpet.

As deep-space data is increasingly culled from super telescopes, hand-rendered images take on a historical significance—soon they’ll comprise the best record of the universe as we believed it to be. One day, we’ll know what the planets of TRAPPIST-1 actually look like, and these drawings will become dated the way flat Earth maps became dated, a product of human imagination and the best information available to us at the time.

“It’s a snapshot of our optimism, in a way,” said Tim Pyle, an artist who works with Hurt at Caltech. “Maybe the chance that a planet is rocky and not a gas giant is only around 50 percent, but that’s how we’ll choose to illustrate it because we’d like to visit it someday, and so we draw it kind of the way we want to believe.”

When the astronaut Alan Bean—a veteran of Apollo 12, and the fourth man to walk on the moon—resigned from the organization in 1981 to paint space art full-time, he labored over the mathematical and scientific accuracy of his work. And yet he found such precision constricting: he often wanted to paint in purples and yellows and blues. The best way to convey the experience of the moon, he thought, was with color, even though the moon itself is gray.

“If Monet painted what he saw,” he told the New York Times in 2009, “we wouldn’t celebrate him today. He painted a little of what he saw but then he painted mostly the way he felt about it.”

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The most immediate threat to space art isn’t technological—it’s political. Trump’s space policy is uncertain, but it looks like we might be scaling back NASA ’s role in space exploring the cosmos. Private companies such as SpaceX, which has promised a manned mission to Mars by 2020, could take up the slack, especially if they’re able to interest the public in the prospect of lunar tourism.

None of this would spell the end for space art, though it certainly stands to change it. “Politicians come and go,” Ramer wrote to me, “but every night you can go outside and look up.” Multiple artists I spoke with hoped that SpaceX and its competitors would widen the market for high-profile space art beyond NASA , especially since there are only so many journal covers to go around. The genre is also finally gaining acceptance in the fine-arts world; galleries that once dismissed the genre as merely illustrative are now opening their doors to space artists. One IAAA member is rendering a series of deep-space images—nebulae, galaxies, images inspired by Hubble—as quilts.

Humans have always been able to imagine more for ourselves than we can achieve, and this idealism lends a touch of heartache to space art. We can picture the world that could exist, the lives we could be having. But the exploration of space isn’t an empty daydream—it’s an actionable one. In recent months, faced with grim news about climate change and the National Endowments for the arts and humanities, I’ve found myself drawn to paintings of exoplanets and neighboring stars and other places I’ve never seen. On a purely aesthetic level, I like looking at images designed to foster a sense of wonder, divorced in part from fact. Space art is utopian, in a way: it chooses to believe a planet is rock and not gas just because we’d like to visit it someday. In its imagination and innovation, it asks us to envision the world on a much grander scale than we normally choose to do—and to retain a certain faith in the engine of discovery, no matter what’s happening on Earth. As Ramer wrote to me: “The stars are still there, waiting.”

Kastalia Medrano is a New York–based journalist.