Astronomical artist Ron Miller has worked with scientists and space agencies to create gorgeous images of planets, stars, and distant galaxies. In this essay, he explains how he creates amazing worlds from scientific data, and shows us a few of his favorite pieces of space art.
Scientists recently discovered the first planet orbiting a double star. It was instantly dubbed "Tatooine" after Luke Skywalker's home world in Star Wars, which also had two suns. In one way, the discovery of Tatooine was routine in the world of astronomy: Extrasolar planets—-worlds orbiting stars other than the Sun—-have been discovered in wholesale lots over the past couple of decades. More than 600 have been confirmed so far and hundreds more are waiting in the wings. Similarly, extrasolar worlds like Tatooine are old hat to space artists, who have been depicting them for nearly a century. But "Tatooine" the exoplanet sparked passionate discussion and newfound interest among an incredibly diverse group of people who wanted to know what this could tell us, if anything, about habitable worlds, space exploration, and more.
We now know planets like Tatooine are there . . . but so far, they are only tantalizing dots in a photograph, a blip on a graph, a series of numbers in a table. These are meaningful data, of course, but how much do they tell us about what these worlds look like? It's all well and good to know that Gliese 581 g orbits its star in 37 days at a distance 146 thousandths that of the Earth's distance from the Sun and that it has a mass of 3.1 to 4.3 times that of Earth and a radius 1.3 to 2.0 times larger. But what would we see if we were to actually visit an exoplanet like Gliese 581 g? How can we bring data alive when the data we're dealing with is light years away?
Astronomical artists, just like other types of artists, have special knowledge, experience, and education to guide our hands when we're working to bring data and information to life. Our illustrations are examples of educated guesses. A police artist, for instance, can produce a credible likeness of a suspect without ever having seen the subject. A forensic artist works with only a fragment of bone and an intimate knowledge of anatomy, and can recreate a face from a bare skull and even tell us what the victim's habits were and what they liked to eat. These artists accomplish such feats because of their intimate knowledge of human anatomy and behavior. Likewise, a specialist in scientific illustration can show us with considerable accuracy what a dinosaur looked like. An astronomical artist does exactly the same thing in visualizing the landscapes of other worlds.
In the artwork I create, for example, I follow a tradition that goes back at least to the mid-nineteenth century. The first artist to pursue astronomical art as a full-time profession was Lucien Rudaux (1874-1947). He was a French commercial artist-turned-astronomer. Combining these skills, he produced a long series of popular magazine articles and coffee table books packed with his spectacular artwork. Based on solid astronomical knowledge, Rudaux's paintings—-rendered in an almost impressionistic style—-look for all the world as though he set up an easel and painted the landscapes of the Moon and Mars from life. He was the first to add an element of believability to space art. And so accurate was his work that even some eighty-odd years later many of his paintings hold up against the best astronomical paintings done today.
If Rudaux is the grandfather of modern space painting, Chesley Bonestell (1888-1986) was the father. He was a classically trained painter who began his career as an architectural renderer. Some of his first jobs included contributing to the design of the Golden Gate Bridge and the Chrysler Building. He later went to Hollywood where he worked as a special effects matte artist, creating scenes for Citizen Kane and The Hunchback of Notre Dame. He always had an interest in astronomy. Using the unique techniques he'd learned in perspective and special effects, he began producing astronomical paintings in the mid-1940s. When Bonestell's work first appeared in Life magazine it was a revelation. No one had ever seen anything like it before. These weren't just paintings — these were more like post cards from the planets. Combining meticulous scientific research with the skills of an extraordinary artist, Bonestell's space paintings looked for all the world like photographs taken by astronauts . . . 25 years before there were astronauts. He set a standard that every space artist strives for to this day.
When I sit down to create an astronomical scene, I have two goals. The first is to create a good landscape painting. After all, all the accurate science in the world is gone to waste if the painting is lousy. The second goal is to make sure that the subject is being depicted correctly. This is no different than if I were doing a portrait; I have an obligation to make the painting at least resemble the sitter. Likewise, if I say that my painting depicts Saturn as seen from its moon Titan, I should make sure that's just what it does.
This means research, and sometimes a lot of it. In fact, there has been more than one occasion where it took longer to research a painting than it did to create it! Worse, what with the speed new information comes in, I've had entire paintings go out of date while I've been working on them. This research comes in part from my own extensive library and files. I also consult research from current journals and as well as the scientists involved in new discoveries. By drawing my data from a diverse collection of sources—-everything from astronomy to geology, from meteorology to oceanography—-I can create a visualization that might be more complete than if I had based it on information from only one discipline.
One of the most satisfying illustrations I've created was for the exoplanet Gliese 581 d. This was the first potentially Earth-like extrasolar planet discovered. Earth-like, that is, if your definitions are broad enough. It's a rocky planet like our own, but much larger and more massive. Data coming in revealed that its surface gravity may be twice what we experience here on Earth. Its sun is a red dwarf star, not as bright as our own, and the planet orbits very close to the star. The planet may also be tidally locked—-meaning that one side perpetually faces its star. This side would be steaming under an eternal noon while the hemisphere facing away from the star would be dark and frozen.
Astronomers think it's possible that Gliese 581 d might also have liquid water on its surface. In fact, it might even be entirely covered in water. I decided on a scene set on the rocky shore of a large lake or sea. The rocks are barren. The water would look deceptively still because waves would be flattened by powerful gravity. Although it is not far away, the star would still not be very large in the sky and its reddish light would give a carnal glow to an already overheated landscape. The atmosphere of Gliese 581 d would be thick and heavy and I conveyed that with low, ominous clouds.
My goal with my rendering of Gliese 581 d, of Tatooine, and of other exoplanets that I depict is to create a beautiful painting that inspires a sense of wonder in the viewer but can also serve as a tool that enables scientists to visualize and better understand those pinpoints of light in their telescopes. Astronomical paintings serve to bring these mysterious and incredible extrasolar planets to life, and I hope they inspire us, as they inspire me, to find important connections between art and science in today's world.
Ron Miller is an illustrator specializing in astronomical art. He contributed over 100 paintings for Scientific America/FSG's recently released iPad app, Journey to the Exoplanets.
Beta Hydri Possible Planet
Kepler 16b, also known as Tatooine