Mars photo shows the Red Planet from above in "true" color for the first time ever

Twenty years ago, the European Space Agency (ESA) launched Mars Express to explore the Red Planet. Since then, scientists have gathered an immense collection of data, enabling them to learn more about everything from canyons and craters to dust storms and hidden ice.

Now, the High Resolution Stereo Camera (HRSC) team has presented a global color mosaic that captures “Mars as never seen before.” It shows the planet in spectacular detail and highlights both surface color and composition.

The vantage point rests about 1,550 miles above the Valles Marineris canyon system, revealing an enhanced view of Mars without its polar caps, thanks to the relatively low altitude.

Each pixel in this simulation covers about 1.24 miles on the surface, offering a closer look at darker grey-black volcanic sands and lighter patches where clay and sulfate minerals appear.

Valles Marineris comes to life

Dr. Ralf Jaumann from the German Aerospace Center (DLR) led efforts that connected fresh camera techniques with years of observations.

His team’s mosaic blends red, green, and blue filter views, adjusting each color band to highlight hidden surface variations.

The image is more than a standard snapshot. It uses individual color channel stretching, so details stand out in ways impossible with a simple “beige to brown” depiction.

Through this approach, a “large scar” appears across the planet’s face, also known as Valles Marineris. Its length of thousands of miles has always drawn attention, but the mosaic’s clarity makes it stand out even more.

By examining the sharp color shifts, researchers can explore how ancient volcanic materials, dust deposits, and other compounds formed the terrain we see today.

Shapes, light, and Mars’ true color

Researchers wanted to form a cohesive image of Mars by stitching smaller images together. A single frame is simple to enhance, but it becomes tricky when combining multiple pictures.

Different angles and shapes come into play. If experts misjudge the spacecraft’s location or the camera’s orientation, the resulting mosaic can end up with misaligned patches.

They also needed to address how sunlight falls across various parts of the planet.

Looking at a single picture of Mars is pretty easy – you just adjust the brightness and contrast to see it better. But when combining several images into one, it becomes more difficult.

Two big problems come up: one is about shapes and angles, and the other is about light.

The strength of the sun, the planet’s reflectivity, and shifting atmospheric dust all change how each region looks.

Small hills and slopes facing the sun can appear brighter, even when they share the same basic composition as adjacent areas.

Making sense of dusty atmospheres

Mars is famous for its dust storms and ever-changing air quality. That’s because Mars has a lot of dust in the air, and the amount of dust changes with the seasons.

In some images, the atmosphere looked hazy, bright, or blurry. Scientists have tools to measure how dusty the air is by examining differences between sunny and shadowy spots. However, that method only works if shadows are clear and large enough.

Most of these can be fixed with computer tools. But sunlight is harder to adjust because slopes or hills that face the sun look brighter, even if they aren’t more reflective.

Because of that, researchers mostly preserved the original illumination in each picture. They adjusted overall brightness so the mosaic would seem uniform, yet they did not remove every bit of shadow.

They recognized that human eyes can interpret shapes using light and shadow alone, so an entirely shadow-free map might cause confusion.

Fitting the pieces like a jigsaw puzzle

In older attempts, matching brightness to a legacy map from another mission helped merge black-and-white images.

There was no reliable true color map of Mars to use, so the team performed a more modest adjustment for color data. This helped make sure the images looked good when combined.

Initially, they focused on displaying color differences within each frame, filling in broad swaths with an average red. That kept finer details visible, though the overall impression was mostly red on a wider scale.

Later developments expanded the mosaic’s range. Between 2015 and 2017, Mars Express sometimes captured shots from high above, covering bigger regions than usual.

Although the spacecraft typically aimed for close-up imagery, these wide-angle pictures enabled researchers to cross-reference color changes over large sections of the planet.

By blending these distance-based views with the near-surface ones, they edged closer to showing an entire globe with consistent color and contrast.

Overlapping frames

The year 2019 saw a series of new high-altitude images that overlapped significantly with previous frames. That overlap raised the possibility of a complete mosaic where each picture connected to others.

Because the spacecraft flies in a big oval path around Mars, it sometimes takes pictures from far away and sometimes from close up.

When all these shots came together, scientists replaced partial color references with a more global model that reflects large and small-scale differences. These showed color changes across much larger areas than usual.

The group integrated these extensive images to fill gaps and polish the big picture. As a result, the mosaic grew more comprehensive with every addition, reducing abrupt seams and strange brightness jumps.

Now, enthusiasts and experts alike can scan Mars with sharper context, comparing volcanic plains, canyon floors, and everything in between in one continuous map.

Mars in true color is huge for science

Darker grey areas reveal basaltic sands left behind by ancient volcanic events. Lighter sections highlight clays and sulfates. While dust storms come and go, these rock formations persist.

Human eyes can usually tell what shape something is just by how light hits it, so it’s not always helpful to remove those shadows.

Subtle differences in Mars’ true color and brightness offer clues about the past, from water activity to mineral creation.

Surface features like Valles Marineris dominate the image, but smaller craters and ridges speak volumes about Mars’s geologic evolution.

The entire mosaic provides a way to piece together distinct eras of the planet’s story without losing local details.

By layering decades of exploration, the HRSC team has taken a large step toward a clearer portrait of Martian geography, both from orbit and on the surface.

The full study was published in the journal Icarus.

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