Mars isn't actually red. Well, it is, but honestly, it’s more of a butterscotch or a dusty salmon color once you get past the postcards. When you look at a picture of mars surface beamed back by the Perseverance rover or the old-school Curiosity hardware, you aren't just looking at a raw photo. You’re looking at a mathematical interpretation of light.
Space is beige. Or pink. It depends on who’s processing the data at NASA's Jet Propulsion Laboratory (JPL).
Most people think a camera on a rover works like an iPhone. It doesn't. Your phone has a single sensor with a Bayer filter that tries to mimic the human eye instantly. A rover like Perseverance uses Mastcam-Z, which carries a series of filters. It takes multiple shots in different wavelengths—some of which humans can't even see, like infrared—and then scientists back on Earth have to stitch them together. This process, called "color calibration," is where things get weird.
🔗 Read more: How Do I Carrier Unlock My iPhone? The Brutally Honest Truth About Getting It Done
The Great Color Debate: Blue Sunsets and Red Dust
If you stood on the Martian surface today, the sky wouldn't be blue. It would be a murky, pinkish-tan. This is because the atmosphere is choked with fine dust particles that scatter light differently than our thick, nitrogen-rich atmosphere. On Earth, our air scatters blue light (Rayleigh scattering), giving us a blue sky and red sunsets. On Mars, the dust particles are just the right size to scatter red light, which means the sky stays red during the day, but the area around the sun turns blue at sunset.
It's literally the opposite of Earth.
When NASA releases a picture of mars surface, they often use "white balancing." This is basically a "what if" scenario. They adjust the colors so the rocks look like they would if they were sitting under Earth’s lighting. Why? Because geologists need to recognize minerals. If everything is bathed in a weird orange glow, a geologist might miss a vein of hematite or olivine. By shifting the white balance to "Earth-like" conditions, the familiar colors of basalt and iron-rich clay pop out.
But it’s technically a lie. A helpful, scientific lie.
Why the 1976 Viking Photos Were "Too Red"
We've been messing this up for decades. When the Viking 1 lander touched down in 1976, the first images showed a sky that looked surprisingly like Earth's. People were thrilled. Then, a few hours later, NASA updated the calibration, and suddenly the sky was a deep, neon orange.
Carl Sagan was actually there for this. He famously noted that despite the pressure to make Mars look "hospitable," we had to respect what the sensors were telling us. The early Viking photos were over-saturated because the calibration targets—little strips of colored plastic on the lander—were coated in Martian dust almost immediately. If your "true white" reference point is covered in orange dust, your whole photo is going to look like it was shot through a bottle of Fanta.
Raw Data vs. Public Relations
You can actually go online right now and see raw images. NASA’s raw image feed for Perseverance is a chaotic mess of black-and-white thumbnails and weirdly tinted squares. These are the "real" pictures.
Each picture of mars surface you see in a news headline has gone through a pipeline:
- De-mosaicing: Turning raw sensor data into a grid of pixels.
- Flat-fielding: Removing the shadows or artifacts caused by the camera lens itself.
- Radiometric calibration: Converting pixel brightness into actual physical units of light (photons).
- Color Mapping: Deciding whether to show "true color" (what you'd see), "natural color" (adjusted for clarity), or "false color" (using infrared to highlight minerals).
If you see a photo where the rocks look bright blue or purple, that’s false color. NASA isn't trying to trick you. They're trying to show you where the water-altered minerals are. Blue usually indicates a different mineralogy than the surrounding red dust.
The Resolution Myth
Don't let the 4K videos on YouTube fool you. Mars is a low-bandwidth environment.
📖 Related: How to restore deleted messages on android: What you actually need to do before it is too late
The rovers don't have a high-speed fiber connection. They have to wait for an orbiter—like the Mars Reconnaissance Orbiter (MRO)—to pass overhead. The rover sends data up to the orbiter, and the orbiter beams it back to the Deep Space Network on Earth. Because the "upload speed" is slow, rovers often send back tiny "thumbnail" images first. Scientists look at the thumbnails and decide which ones are worth the "data cost" of downloading in high resolution.
This is why some parts of a picture of mars surface look blurry while a specific rock in the center is crystal clear. They're being selective with their bits and bytes.
The "Face on Mars" and Human Psychology
Our brains are hardwired for pareidolia. We see faces everywhere. In 1976, the Viking 1 orbiter took a photo of the Cydonia region that looked exactly like a human face staring up into space. It fueled decades of conspiracy theories about ancient Martian civilizations.
Then we went back.
In 2001, the Mars Global Surveyor took a picture of the same spot with much higher resolution. The "eyes," "nose," and "mouth" vanished. It was just a mesa. A pile of rocks and shadows. This is the danger of a low-resolution picture of mars surface. Shadows at a low sun angle can turn a regular hill into a monument.
Current Tech: The Perseverance Advantage
Perseverance is carrying the most advanced camera system ever sent to another planet. The Mastcam-Z can zoom in on a target the size of a house from three miles away. It’s also capturing video with sound.
Hearing the wind on Mars while looking at a high-res picture of mars surface changes the experience from looking at a map to visiting a place. The cameras are also used for navigation. The rover "sees" in 3D by using stereo pairs of cameras (left eye and right eye). It builds a "mesh" of the terrain so it can drive itself without crashing into a rock while the humans on Earth are asleep.
Seeing Through the Dust
Mars has global dust storms. Every few years, the entire planet gets shrouded in a haze so thick that you can't see the surface from orbit. For solar-powered rovers like the late, great Opportunity, this is a death sentence. The sky goes black, the "picture of mars surface" becomes a wall of gray, and the batteries die.
📖 Related: Google What Time It Is: Why Your Internal Clock and Your Browser Don’t Always Match
Perseverance and Curiosity don't have this problem because they run on nuclear power (RTGs). They can keep snapping photos in the middle of a literal apocalypse.
How to Analyze a Mars Photo Yourself
If you want to be an expert at reading these images, look for the "calibration target." Every rover has one. It's usually a small, circular dial with colored blocks on it. By looking at how those colors appear in the photo, you can tell how much the image has been processed.
- Look at the shadows. If the shadows are pitch black, it’s a high-contrast raw image. If they are filled in with blue or orange light, it’s been processed to mimic Earth’s atmospheric scattering.
- Check the horizon. A sharp, clear horizon usually means the photo was taken on a "clear" day (for Mars). A fuzzy, yellowish horizon means a dust storm is brewing.
- Find the tracks. The rover tracks are the best way to see the "true" color of the soil. The surface is often covered in bright red dust, but the wheels churn up the ground to reveal darker, gray or black volcanic sand underneath.
Basically, Mars is a grey planet wearing a very thin red sweater.
The Future: Bringing the Pictures Home
We are currently in the middle of the Mars Sample Return mission. The goal is to bring actual rocks back to Earth. While a picture of mars surface is worth a thousand words, a physical gram of Martian dirt is worth a billion pixels. Until then, we rely on these robotic eyes.
The next time you scroll past a photo of a Martian crater, remember that you’re looking at a world that is fundamentally alien. The colors are "wrong," the shadows are "weird," and the sky is the color of a faded brick. But it’s the only other world we can see in this much detail.
To get the most out of your Mars viewing, stop looking at the "official" NASA posters and go to the JPL Raw Image Archive. You can filter by camera, sol (Martian day), and even the specific atmospheric conditions. It’s the closest you’ll get to standing in Jezero Crater without a spacesuit. Look for the "left" and "right" Navcam images to see the world in true stereo depth—it’s a completely different experience than a flat, processed panorama.