How Did We Draw The Planet Before We Actually Saw It?

The story of our not-so-Blue Marble

How Did We Draw The Planet Before We Actually Saw It?

I spend a large portion of my work day feeling confused. I start my days bewildered by advances in niches of science that I only recently learned existed. Chatting with experts usually resolves my initial confusion, but immediately after spawns more: Every question begets an answer and more questions, ad infinitum. 

To me, there’s no more jolting brand of bewilderment than doing a double take on the everyday things. New discoveries may lurk in the mundane. The ubiquitous, almost cartoonish image we have in our heads of the Earth might seem like a trivial matter now, but seriously, how did we get there? 

So let’s first lay out what I mean by Earth’s appearance. How did we know how to draw Earth until we sent cameras and people into space to snap some pictures? Sure, we know that land is greenish, oceans are blueish, and that mapmakers have spent millenia tracing the contours of continents, but these details tell us about Earth’s appearance in theory more than in reality. Think of it this way: I know the color of my hair and skin, as well as the shape of my head and mouth, yet I still study the bathroom mirror in the morning to see who or what I’m working with that day. What about the appearance of that Earth—the “woke up like this” Earth?  

Turns out this wasn’t a trivial problem; and in some ways, we kinda didn’t know what Earth actually looked like until we saw it from space. 

De La Beche's Earth / Wikimedia

Let’s time-hop a little. Notable depictions of Earth from the century prior to space travel offered a context to imagine what Earth would look like to an otherworldly observer. In 1834, British geologist Henry De la Beche etched Earth floating in space, and depicted familiar continents overlaid by flows of currents or clouds. His depiction of continents reflected the work of cartographers before him, and De la Beche’s image placed a scientifically accurate image of Earth within a cosmic neighborhood. In the late 1800s and early 1900s, French astronomer Camille Flammarion imagined Earth viewed from the moon and from Mercury—our homeworld a mere speck from these distant vantage points, as if to simultaneously suggest that we’re cosmically insignificant and perhaps not alone. Decades later, in 1956, the book The Exploration of Mars featured an illustration by Chesley Bonestell that filled in colors of Earth’s grasslands and deserts, with various blues in the ocean, and shaggy clouds that neatly streaked the globe. 

Bonestell’s depiction was getting somewhere just as the Space Race was hitting its stride. 

Adapted from Chesley Bonestell's paintings in The Exploration of Mars

In the two years before and after Bonestell’s Earth, humans as a newly spacefaring civilization successfully launched a series of firsts: the first satellite, Sputnik (Russian for "fellow traveler") carried the first dog, Laika (Russian for “bark”) into orbit. Neither satellite nor dog brought cameras into orbit, but a few years prior the US Naval Research launched a rocket with a 16mm camera that captured the first mosaic of Earth images in color, from 100 miles up. It wasn’t high enough to behold the Earth in its entirety, but it produced a collated image of a tropical storm in the Gulf of Mexico. The picture foreshadowed the role of satellites in meteorology, and the role clouds would play in our global self-image. 

First color photo of Earth from space / Wikimedia

First photograph of Earth with the Moon / Wikimedia

 The space-firsts continued deep into the 1960s. The first Earth selfie was published in 1965. In December 1966, the satellite ATS-1 retrieved the world’s first photograph of Earth with the Moon. ATS-1 also brought us the first “full disk” images of Earth. These black-and-white images captured an apparent flaw in humankind’s perception of Earth’s appearance: clouds. Swirly, diverse, turbulent, and everywhere, clouds were notably scarce in previous artistic representations of our planet. 

Clouds carried on their quiet prominence in November 1967, when ATS-3 snapped the first full disk images of Earth in color. Then came the Apollo 8 mission in December 1968, when astronauts reached the Moon for the first time. The mission pinged back the first whole Earth photo by a person, and subsequently, the first pictures of Earth from the Moon. Things only got more iconic after that. Fast forward one year, and you’ve got Buzz Aldrin posing for Neil Armstrong on the Moon’s surface, and Michael Collins capturing a mind boggling “Earthrise” from lunar orbit. Then in 1972, came the famous “Blue Marble,” a shadow-free view of our full, cloudy globe that became one of the most reproduced images of all-time. In each of these images, clouds enshrouded the pale blue dot’s oceans and dry land. Judging by the photos alone, an alien might have deemed that the majority of Earth’s surface was white.

Apollo 8 photo of a cloudy Earth, 30,000 kilometers away / Wikimedia
“The Blue Marble” from Apollo 17 / Wikimedia

I’ll admit: I’ve previously felt a little let down by clouds obscuring an otherwise spectacular view of Earth’s continents and oceans. It’s worth saying that artists and scientists alike seem to agree with me: In the early 2000s, NASA released a new generation of Blue Marble images without clouds. But depictions didn’t only nix clouds on purpose to highlight land and sea; they also just overlooked clouds because we simply didn’t know as much about them. But that’s not the whole story. There’s a lot that we didn’t know about Earth’s clouds until the first days of satellites and space barks.

“We think of Earth as the blue planet, but if you look at Earth from space, it's actually more white than it is blue,” Graeme Stephens, co-director of NASA JPL Center for Climate Sciences, told me. “Earth is covered with this thin white veil.”

Stephens served as the principal investigator behind NASA’s satellite CloudSat, which operated from 2006 until 2023. CloudSat had a radar instrument that helped estimate hurricane intensity and establish links between pollution and precipitation. “What these active instruments did was provide a kind of truth,” he told me. Satellites predating CloudSat only gave 2D images of clouds, and scientists wanted additional information in the  third dimension. For example, the height and depth of a thunderstorm influence whether it will precipitate dangerous hail. CloudSat was a foray in that direction. Its lasers let scientists map out the density and quantity of particles in the sky. Which led scientists to naturally wonder, “How much cloud is there on Earth?” Stephens asks.

Physicists in the 19th century estimated that clouds covered half the Earth without making any direct measurements. Energy balance was the key to these calculations. The physicists assumed that clouds reflected 80 percent of the sunlight (a metric known as cloud albedo). So, a 50 percent cloud cover gave them a reasonable estimate of how much radiation gets trapped on Earth.

Turns out the physicists got both albedo and cloud cover figures wrong. Cloud cover was higher, but albedo was lower, at about 31 percent. “That means clouds weren’t as bright as our historical forefathers thought they were,” Stephens said. “Now we have exclusive measurements around Earth orbiting satellites, and we know exactly how much they reflect.” Modern measurements have converged on a global cloud cover fraction of about 70 percent. That means clouds obscure about two-thirds of Earth’s surface at any given moment.

Thanks to satellite technology, clouds finally came into focus. “As we started to see Earth in a more holistic way from space, we began to understand cloud systems,” Stephens told me. For the first time, scientists had the tools to understand cloud clusters, of which an individual cloud is always a part and never exists in isolation. What we see as one cloud is generally part of an array of clouds. “Clouds organize themselves in very large-scale systems—the scale of which we couldn't conceive until we saw them from above from space.”

Revelations from space helped us make sense of climate change. In 1986, NASA satellites confirmed the hole in the ozone layer. From an orbital vantage space, scientists captured evidence of polar ice collapsing, deep blue oceans turning more green. Looking at Earth from space revealed that clouds played a much more complex role in climate change than previously thought. Stephens noted that researchers tracked clouds in the atmosphere’s upper and lower layers that they previously believed sat somewhere in the middle. That distinction is important, he told me, because the altitude changes the role of clouds in regulating the climate. The simplified view is that low clouds reflect solar radiation for a cooling effect, whereas high clouds can absorb heat from below for a heat-trapping effect. High clouds exacerbate warming and low clouds mitigate it. 

Clouds are a critical variable in our planet’s climate math. They play a part in how much energy comes in and leaves Earth in the whole global temperature equation. Alarmingly, in the last 20 years, low clouds have been gathering. “That layer is not quite reflecting as much sunlight back to space.” Although the change in reflectivity is modest, it suggests that Earth’s heat content is increasing. The planet is warming—and at an accelerating pace. 

So why not just create more bright planet-cooling clouds? Now that we know what Earth looks like and, on some level, why, we might ask how to give it a makeover. On the surface, geoengineering is an alluring proposal. In fact, Stephens told me that “cloud physics grew out of a desire to modify clouds and make more rain.” 

But history is full of good intentions gone awry. While talking about so-called cloud seeding or geoengineering plots, Stephens digressed to cane toads. The sugar industry introduced cane toads to Australia last century to control cane beetles. The invasive poisonous toads proliferated and began killing native reptiles. “This is an example of fiddling with a system that you don't understand, and you have no appreciation for the knock-on effects,” he cautioned. 

Although Stephens has encouraged a new generation of climate models that better incorporate clouds into the picture, he says we still don’t know enough to begin tinkering with the atmosphere. “It's a dicey situation to go down. Geoengineering a system that you don't fully understand is not necessarily a good place to begin,” he said. As far as we have come in understanding how the world looks and works, perhaps we’re still a little bit confused.