When NASA designer Robert Simmon bought one of the first iPhones in 2007, what he saw when he turned it on startled him.
The image on the phone's startup screen was one he had designed. Known as the "Blue Marble," it displayed a beautiful picture of the Earth from space, composed of many satellite images taken of our home planet.
The "Blue Marble" is perhaps Simmon's most famous piece of work. But the designer, who works at NASA's Earth Observatory, is interested in more than just creating pretty pictures. He wants the images he creates to help people better understand how the Earth works.
"Capturing people's attention with true color imagery is pretty easy," Simmon explained in a 2012 presentation he gave to attendees at the American Geophysical Union conference in San Francisco. "But to get across more complex story, that's really hard. ... If we want to tell more complex stories, we have to use different techniques."
Those techniques use tools from cognitive science, graphic design and cartography to display complex information in a visual form. The field is often called information visualization. Simmon is one of its expert practitioners.
"There's this information overload that people are experiencing, and visualization is a great way to handle that," said Drew Skau, a visualization architect at the Bay Area company Visual.ly, a website for people to create, share and discuss visual content.
Skau, who is getting his doctorate in the field of information visualization, said he admires how Simmon displays large quantities of data in a beautiful, accessible way.
Simmon and his colleagues at the Earth Observatory see their audience as anyone interested in understanding how the Earth works, from school kids to scientists. One way they make their work accessible is by tying it to current events.
"What volcanoes are erupting, is there flooding, are there storms?" said Simmon.
If there's an extreme event taking place, NASA probably has a satellite that has taken a picture of it. Simmon finds the files and then he will use software like Photoshop and Illustrator to adjust the images so they make sense to the human eye.
Setting up the teachable moment
Sometimes, Simmon and colleagues at the Earth Observatory will create additional maps and images that help fit the event into a larger story, turning a one-off image into a teachable moment about our changing planet.
When wildfires in Siberia made the news recently, for example, Jesse Allen, a member of Simmon's visualization team, made two images using data from the MODIS satellite (ClimateWire, Aug. 12).
One showed a natural-color overhead view of the smoke from fires in part of Siberia. The other, a map of the surrounding area, showed how temperatures in that part of the world were significantly -- about 30 degrees Fahrenheit -- warmer than average.
It was this second map that took the event -- Siberian fires -- and placed it in a larger climate change context.
The text that accompanies the images points out that while there are many complex atmospheric factors that produce heat waves, scientists agree that global warming has made it more likely for heat waves and large fires to occur.
"I want imagery that people not only think looks interesting, but that they learn something from," said Simmon.
Alberto Cairo, a well-known design expert who has written a book on information graphics called "The Functional Art" and who teaches at the University of Miami, said the work that Simmon does at the Earth Observatory appeals to him because it is multimedia, using infographics, text and photographs to tell stories about the Earth.
"So that creates a very immersive learning experience," Cairo said.
Photoshopping a volcano
Over time, Simmon has perfected the art of transforming satellite images into people-friendly pictures. On a recent day, he opened an image file on his 30-inch monitor and set to work on it.
The image was of a volcano called Rabaul, in Papua New Guinea. It looked a little like an underexposed camera shot -- dark, without much color.
"The reason it's so dark is because there are 11 bits of data in a 16-bit file," Simmon said. "So in Photoshop, what you need to do is stretch the information across your whole range of available values."
As Simmon clicked and dragged, the image clarified. Clouds whitened; land turned an expected shade of green. The designer explained that his goal is not to make an picture that shows the Earth exactly as the satellite sees it, but to make an image that the human brain can understand and relate to.
"So what I need to do is manipulate the image to match all the processing that our eyes and brains are doing for us." he said. This includes removing the blue cast that comes from the atmosphere and adjusting things like white balance and overall contrast.
"In a sense, I'm actually doing what a mapmaker would do, which is [creating] a semi-idealized representation of the surface."
Charlie Loyd, a satellite imagery specialist at MapBox, a Washington, D.C.-based company that makes custom Web maps, said he had long admired the work coming out of the Earth Observatory, and one day realized that the visualizations he liked the most came from one person -- Simmon.
Loyd said a challenge in visualizing science information is catching people's interest.
"The public is often really interested in topics of geology, meteorology, land use, et cetera, but they don't know they are," said Loyd. "Robert is great at finding the 'cool factor' without dumbing things down."
Since climate science has become a politically charged topic, Simmon has also worked to gain public trust by creating graphics on a wide range of Earth science topics. The Earth Observatory has published beautiful images of city lights at night, shots of tornado paths through Oklahoma and overhead views of fire scars in Colorado.
MapBox's Loyd also highlighted Simmon's ability to pack a lot of information into a relatively simple looking graphic.
Confusing data became a hockey stick
An example of this is his version of the famous "hockey stick" graph showing Earth's temperatures rising rapidly in recent decades.
This graph, while not as striking as some of the maps Simmon has produced, shows the Earth's temperature rising sharply in the last few decades. What makes it so powerful is that he incorporates four independent temperature data sets, said Loyd.
"I think most people making that visualization would assume that having multiple lines would confuse the viewer," said Loyd. But in the graphic, those four sources, corroborating each other, make the case for a warming world even stronger.
Simmon does more than just create images. He also speaks and writes often on how to improve the communication of scientific information to the public. He tweets regularly about design and Earth science and has recently been writing a series about appropriate uses of color on his blog, Elegant Figures.
One of the most inappropriate uses of color, say Simmon and many others in the graphics community, is the overuse of the rainbow color scale.
The reason designers dislike the rainbow color palette is based in the science of how our brains see color. When maps and graphics use a rainbow scale, the transitions between the colors are not even. There is a sharp contrast in the bright cyan and yellow areas, but greens, for example, tend to blend together.
This could be misleading. When a rainbow palette is used in a graphic, the yellow and green values are often very close to each other. But to our eyes, they look like there is a huge difference between them.
Rainfall maps often use this scale. To our brains, the areas in yellow will seem much different than those that are green, even when the actual difference between the numbers is not that great.
Even though the rainbow scale is common in scientific figures, "I would almost never allow a rainbow palette to be published," Simmon said.
Simmon, who has a master's degree in materials engineering and is self-taught with no formal training in design, noted that the pace of new satellite missions has slowed in recent times and some, like the MODIS satellite, are aging. But as long as there are new data and images to work with, he plans to continue making graphics that explain how the Earth works.
The driving force behind his work, he said, is clarity. "There is no ideal way to do anything, but there are bad ways to do things," he said. "So I try to minimize the bad."
Correction: An earlier version of this story incorrectly attributed maps of Siberia wildfires to Robert Simmon.