Striking and colorful images of space are everywhere — in magazines and textbooks, on stamps, all over the Internet, and on the cover of academic journals. We might think these images are simply high definition snapshots from powerful telescopes, but the truth is actually a lot more involved.
The process is closer to data visualization; astronomers combine information recorded from telescopes over time in order to make measurements, but for public outreach images, they manipulate these data using image-editing software like Photoshop and GIMP. Much of the information that telescopes capture occurs outside the range of optical light, in wavelengths beyond what the human eye can perceive. So, explains University of Manitoba professor Dr. Jayanne English, when it comes to images of space, seeing is not believing.
ARTpublika Magazine spoke to Dr. English about her groundbreaking work creating these images in the field of astronomy. Public outreach images are aptly named because their purpose is to “pique [the public’s] interest” and “build bridges between the public and the scientists.” In order to do this effectively, though, scientists must have a grasp of “visual grammar” — or the basic concepts of art and design. Dr. English championed this notion when she was the coordinator of the Hubble Heritage Project in the late 1990s, which produced a stunning image of space once a month using archival data.
She was particularly well suited for this role because of her background in both art and astronomy. She studied experimental arts at the Ontario College of Art and Design, then subsequently earned her Bachelor’s and Doctorate in Physics and Astronomy. This dual expertise lent her a certain authority in collaborating with her colleagues at the Heritage Project. “Everybody has an idea about what their data should look like. We would have to tell them, ‘Well, you don't stick [the subject] dead center. That's a static image and people won't look at it.’” She also taught them “why you choose certain colors to give spatial depth and [about] composition in general.”
Ultimately, this process is a means of converting images in the “logic tradition” — which are primarily quantitative and statistical — to the “Western image tradition,” which are more naturalistic. “Scientists,” she points out, “prefer to make contour plots,” but “the public doesn't understand” these kinds of graphs. As such, in order to successfully complete this conversion from logic tradition to Western tradition, scientists must have a basic grasp of visual grammar.
In her seminal journal article, “Cosmos and Canvas: Visual Art Techniques Applied to Astronomy Data” (2017) Dr. English writes:
“The method of arrangement incorporates the techniques of composition and colour harmony…Visual grammar allows one to create an image that engages the viewer and retains their attention…[It] can create spatial depth, emphasize intriguing fine-scale detail, and deliver rich colours. Often it can help one communicate some of the scientific content without total reliance on a legend.”
In this way, she tells ARTpublika, “the image isn't supposed to tell you everything about the subject,” but it should still maintain its scientific integrity.
In her paper, Dr. English references Van Gogh’s The Starry Night (1889) as an illustrative example. “The church,” she writes, “is not in the dead centre of the painting. That would be… as boringly comprehensible as a bull’s eye target — the viewer would instantly assess the subject and stop looking at the picture plane. The alternative off-centre, dynamic placement retains the viewer’s attention.”
A Hubble Heritage Project image of two galaxies emulated this technique. Before applying elements of visual grammar, the galaxies looked “as flat as two eggs on a cast iron frying pan.” But “a simple rotation of 180 degrees and a tight cropping… sets up a composition similar to The Starry Night.” The altered image was so compelling that it was included in Life Magazine’s 1999 issue of The Year in Pictures.
This example illustrates the amount of decision-making that goes into creating a public outreach image.
“The data has to come in and be processed, the hardware noise has to be removed from the data. You have to combine [multiple exposures]. Once you have the data in the black and white format… there are still lots of artifacts to remove. And you have to then stack the images… pick which energy ranges you're going to use, assign colors to those energy ranges. You have to compose the picture.”
It’s not a swift process; images have taken her up to a year to create. It all proves the point that these images are decidedly not simple snapshots. Dr. English takes issue with news headlines that say “something like ‘Hubble snaps a picture of [x].’ That’s not true.” This is also one reason why image-making instructions are democratized, available for any “citizen scientist” (i.e., someone without an astronomy degree) to access — it reiterates to the public that these images are scientifically valid manipulations, not pictures that correspond 1:1 with reality.
Anyway, we couldn’t physiologically digest a 1:1 snapshot, because telescopes detect a much wider range of energy wavelengths — such as radio waves, infrared, ultraviolet — than the optical nerve can perceive. Dr. English explains: “It’s kind of like if you could [simultaneously] see my skin and my bones.” Telescopes capture what the human eye cannot, and astronomers translate this information into visually harmonious — and scientifically accurate — images for public consumption.
Since her days at the Hubble Heritage Project, these images have come quite a long way. When she first started doing this work, she says, she would take just a few images, “usually from the same telescope… and assign red, green, and blue to each image… It would be very contour like and very simplistic.” As time went on, she said, “We got used to using algorithms like in Photoshop and Gimp that allow you to use different blending modes. We could assign different colors. We started to learn other techniques like masking, which allowed you to — if you had a bright region in one energy — you could mask that down so that you could insert something fainter.” In other words, their techniques grew increasingly sophisticated.
As for the future — like in many fields — they’re learning how to leverage virtual reality technology. With certain telescopes, such as the ALMA, astronomers are often “working in three dimensions,” but these are not three spatial dimensions as we generally conceive of them. In this case, instead of depth, the third dimension is velocity. But, Dr. English says: “We want to get inside of our data.” They want to work with three spatial dimensions, and not just “three dimensions projected onto [a two dimensional computer] monitor.” So the next frontier is hyper-realistic, 3-dimensional computer simulations that occur over time. “They can make a model,” for example, “of a spherical explosion [as it unfolds] in time…So we’re moving into virtual reality where we can… step into our data and do our analysis in three dimensions.”
And as the public starts to engage with these 3-D virtual simulations, we can expect them to retain the same principles of art and design, especially if Dr. English has anything to do with it. It’s worth pointing out another relevant development: she used to call the intersection between aesthetics and astronomy “canvas versus cosmos.” Now, she refers to it simply as “canvas and cosmos,” because she doesn’t “have to do the battle anymore.”
“In the past, astronomers [thought] you could have either or your scientific understanding, or you were doing something that was fantasy life or ‘artsy’… People understand now that there can be the support of their scientific ideas by using techniques from art and design.”
And while it’s true that she doesn’t consider public outreach images pieces of conceptual art, incorporating these artistic fundamentals is essential to accomplishing the image’s purpose.
Indeed, as she concludes her paper:
“Science can be rendered both engagingly and rigorously using visual grammar so that it is relevant to scientists, artists and the general public… If the attempt to balance communication of scientific information and perceptual power is described as a struggle between the culture of science and the culture of art, then in astronomy public outreach images both sides win.”
Note* The Starry Night, and the image of galaxy NGC 2207 and its interacting companion IC 2163, are taken from the paper by Dr. English. All other images are sourced from https://images.nasa.gov.