Exoplanets take many weird and wonderful forms, and we've only discovered a handful of the untold number that exist in our universe. Even though a small number have been directly imaged, most have been identified through indirect methods and in both cases, the actual appearance of the planet is left almost entirely to the imagination. This means that it falls to talented artists to provide an accessible interpretation of what these remote bodies could look like. We spoke to space artist Danielle Futselaar to uncover what goes into illustrating a planet.

With the help of NASA's seven year-long Kepler mission, around 2,000 exoplanets and almost 500 multi-planet systems have been confirmed – from the relatively unremarkable to the incredibly bizarre. Organizations such as SETI and NASA commission artists like Danielle Futselaar to envision and create these remote worlds.

Unlike the high-resolution images sent back from the Hubble Telescope, the details we have on planets outside our solar system is limited to things like mass, radius, density, gravity, orbital periods, distance from host star and atmospheric composition. Guided by scientists, artists transform this data to life.

A brief history of the (illustrated) Universe

NASA began its Space Art program in 1962, four years after the organization was founded. Initiated by James Webb, NASA's second administrator, the program's goal was to present NASA's often complex scientific discoveries in a way that the public could easily comprehend. The agency commissioned famous artists such as Chelsey Bonestell to visualize early astronomical discoveries, such as the surface of Mercury, as well as futuristic visions of space exploration like a vast circular space stations. Many modern day space artists draw inspiration from Bonestell's work.

The first mission to be recorded by artists of the Space Art program was the launch of the Faith spacecraft in 1963. Faith was the last manned mission of the famous and successful Mercury missions. The Kennedy Space Center was opened up to the selected artists to get inspiration and talk to scientists about the more technical aspects of their paintings.

NASA now has a collection of thousands of artworks across a range of mediums, including sculpture and music, that capture the wonder of space and space travel.

From data to drawing board

These days, the media may have changed, but the processes and goals of this type of artwork remain very similar.

Danielle Futselaar is a Netherlands-based graphic designer and illustrator. She currently runs her own digital art and graphic design business, and has worked extensively with space organizations such as SETI and ASTRON. Prior to her space-related work, she did illustrative work for books, including Lucy and Stephen Hawking's George series. Her work has been published in newspapers and accompanied multiple press releases.

Futselaar has done over 10 artist's impressions for organizations like NASA and SETI, and some a bit closer to home for the Netherlands Institute for Radio Astronomy. Her works range from realistic interpretations of exoplanets to gigantic sci-fi Dyson spheres harnessing a sun's energy. She strives for accuracy in all she produces. "I listen to the scientist's wishes," says Futselaar, "because I think their publication deserves an image that supports the scientific work."

Futselaar's work on Kepler 138b, with movement trails to indicate orbiting speed(Credit: Danielle Futselaar)

Kepler 452b was discovered in July of 2015. The planet was labelled as Earth's bigger, older, cousin, and caused quite the stir when it was announced. Futselaar was commissioned by SETI and Jon Jenkins, the Kepler Mission Co-I for Data Processing, to envision what this "older earth" landscape could look like. "[Jon Jenkins and I] started out very imaginative," says Futselaar, "Since this is an older planet than Earth we imagined civilizations might have come and gone. But they decided right away that it would be far too speculative to put in hints of ruins and buildings."

Artist's interpretations are guided by insights from scientists at NASA, and a great deal of careful thought is put into creating an accurate as possible representation of these mysterious landscapes. Futselaar says she initially receives a set of information from scientists and creates a preliminary sketch from that. This is then sent back to SETI for evaluation before it's returned with comments. Discussions are ongoing throughout the process and in the case of Kepler 452b, Futselaar was invited to join in a teleconference to discuss her artwork, with the scientists enthusiastic to answer her questions in great detail. "Scientists are wonderful and passionate people to work with," she says.

Insights from scientists at NASA Ames and the SETI, including a geologist, were also provided to fine tune the work. An early version of her Kepler 452b piece included arcing natural rock bridges stretching across the landscape. These had to be removed, as scientists informed her that the planet's high gravity would not allow for these structures to form.

Reaching the final iteration of a piece takes time. "It took about 10 sketches from beginning to end to come to the final result," says Futselaar.

Futselaar's process behind the Kepler 452b landscape – the natural bridges and ruins were removed at the request of scientists(Credit: Danielle Futselaar)

Although the organizations obviously strive for scientific accuracy, artistic license is not forgotten. While drawing little green men is out of the question (unless some are found), a healthy level of speculation is allowed. Futselaar has done illustration of planet surfaces, occasionally with plant-life, but only when directed by scientists. For her illustration of the young hot Jupiter-like exoplanet discovered by the Gemini Planet Imager Team (below), for example, she was simply instructed to draw a "dull" planet with one star in the background, so imagination definitely has a part to play.

Creating the hot young Jupiter image(Credit: Danielle Futselaar)

A digital medium for a digital world

In the 90s, NASA still accompanied their press releases with analog artwork, commissioning now famous space artists such as Don Davis to put their findings to paper, or more accurately, to canvas. Digital space art didn't take off until the late 90s, so artist's impressions were still created through traditional mediums like acrylics and watercolors. In the modern day, the availability of Photoshop and drawing tablets has changed the game.

Futselaar does nearly all her pieces in Photoshop, using a Wacom tablet and pen. She has done some photographic manipulations, but firmly believes that there is an advantage in illustrations. "When you look at many other astronomy artist's impressions, you'll see that they are photorealistic-manipulations; it isn't real, but it looks real," said Futselaar, "because of that some viewers actually think of it as 'the real deal', actual photographs."

Futselaar's photographic manipulation of the Arecibo telescope, displaying unknown radio waves being received(Credit: Danielle Futselaar)

Photographing these far flung exoplanets is impossible for the moment, and Futselaar and Jenkins both believe that altering photographs can confuse readers into thinking NASA is already taking photos of them. Illustrations provide less confusion, as viewers can easily see that it's meant as an artistic impression.

A digital medium offers more advantages than just reducing confusion. NASA provides the information to artists with a limited period of time before the embargo is lifted, anywhere from a week to a month. Artists must then work to that deadline, all the while collaborating with scientists on all aspects of the illustration. Digital art allows for quick modifications that other forms don't.

With her creation of the Kepler 452b landscape, Futselaar was told she could illustrate a moon. "When I showed them the illustration with the moon on it," says Futselaar "one of the scientists said 'If that moon would be that big or that close, it would crash into the planet'." In Photoshop, fixing this was easy: a quick resizing of layers and the moon was back to a safe, non-apocalyptic distance. These sort of changes in traditional mediums would be incredibly difficult and time consuming. "For me illustrating digitally, especially for science, is ideal."

Futselaar's illustrations usually take her 1-4 working days to complete, depending on the length of the embargo. She mentions that keeping all of the information under her hat for that long can be tough, and with discoveries as cool as Kepler 452b, that's not surprising.

More information: Danielle Futselaar

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