Scientists Discover Strange Gas Leaking From Mars — Is the Red Planet Still Volcanically Active?

 Mars may not be the cold, geologically dead world scientists once imagined. A European spacecraft has detected an unusual gas above cracks in the planet's surface, raising the possibility that hot magma still exists deep underground.

The discovery centers on Alba Mons, an enormous ancient volcano where researchers have identified unexpected concentrations of hydrogen chloride. On Earth, this gas can escape from volcanic systems, making its presence in a particular region of Mars especially intriguing.

If the scientists' interpretation is correct, the Red Planet may still possess active geological processes beneath its frozen surface. And that possibility raises another extraordinary question: could underground volcanic heat create environments where microbial life might survive?

An Unexpected Discovery Above a Giant Martian Volcano

The discovery was made using observations from the European Space Agency's ExoMars Trace Gas Orbiter, a spacecraft designed to study the chemical composition of the Martian atmosphere.

Since beginning its scientific observations in 2018, the orbiter has measured extremely small quantities of atmospheric gases. Among them is hydrogen chloride, a compound that scientists first reported detecting on Mars in 2021.

Hydrogen chloride was already known to appear in the Martian atmosphere during certain seasons. Much of that behavior could be explained by chemical reactions involving airborne dust and water.

But researchers noticed something unusual near Alba Mons, a massive shield volcano in the northern Tharsis region.

Hydrogen chloride was appearing above the same general area during a season when it was not normally expected. Instead of being widely distributed across the planet, the gas was concentrated near volcanic terrain.

The repeated observations suggested that something local might be releasing it.

An international research team, led by Alexander Trokhimovskiy of Russia's Space Research Institute, investigated the mystery. Their findings were published in Science Advances on November 4, 2026.

Strange Cracks May Be Releasing Gas From Underground

To understand where the gas might be coming from, the scientists combined atmospheric measurements with detailed images of the Martian surface.

The ExoMars orbiter carries an instrument called the Atmospheric Chemistry Suite, which can detect tiny amounts of gases by analyzing how sunlight passes through the atmosphere.

Researchers compared its measurements with images captured by the spacecraft's CaSSIS camera.

The images revealed narrow fractures in the volcanic terrain around Alba Mons. Some extended for hundreds of meters, while others were less than a meter wide.

Several of these features were associated with unusual changes in the color of the surrounding ground.

The scientists proposed that the cracks could provide pathways for gas escaping from deeper inside the planet. The discoloration might result from minerals deposited around the openings, similar to deposits formed near volcanic gas vents on Earth.

This does not prove that the cracks are volcanic vents. However, their location near the unusual hydrogen chloride detections makes the connection worth investigating.

The researchers suggest that the gas could originate from a dormant magma system beneath the surface.

If so, Mars may still retain enough internal heat to support volcanic processes, even without visible eruptions.

Why Does the Gas Appear During a Particular Season?

One of the most intriguing aspects of the discovery is its timing.

Hydrogen chloride usually follows a seasonal pattern in the Martian atmosphere. The unusual detections near Alba Mons occurred during early summer in the planet's northern hemisphere, when scientists would not normally expect such localized concentrations.

The researchers believe ice may help explain this behavior.

During the extremely cold Martian winter, temperatures in the region can fall to around minus 120 degrees Celsius. Ice may accumulate inside fractures and temporarily block gases rising from below.

As temperatures increase, the ice can sublimate, changing directly from solid to vapor without first becoming liquid.

That process could reopen the cracks and allow trapped gases to escape into the atmosphere.

The explanation remains a hypothesis, but it offers a possible reason why the gas appears in the same region at particular times of the Martian year.

It also suggests that future observations could test whether the pattern repeats.

Could Mars Still Have Active Volcanoes?

Mars contains some of the largest volcanoes in the Solar System, including Olympus Mons, which rises more than 20 kilometers above the surrounding terrain.

These enormous structures demonstrate that the planet experienced powerful volcanic activity in the distant past.

However, scientists have long debated whether volcanic processes continue today.

Some Martian lava flows appear relatively young in geological terms, and NASA's InSight lander detected earthquakes known as marsquakes. These observations suggest that the planet's interior may still be more active than previously assumed.

The new hydrogen chloride findings add another potential clue.

On Earth, volcanic systems can release gases even when no lava reaches the surface. Similar processes could occur on Mars if magma remains beneath its crust.

Importantly, researchers have not observed an active volcanic eruption or a fresh lava flow associated with the Alba Mons gas detections.

The evidence therefore points toward possible underground magmatic activity, not a volcano visibly erupting.

That distinction matters because Mars may be geologically active in ways that are difficult to detect from orbit.

Could Underground Heat Create Conditions for Life?

The discovery also has implications for one of the biggest questions in planetary science: whether Mars has ever supported life, or might still provide suitable environments for microorganisms.

Today, the Martian surface is extremely cold, dry and exposed to intense radiation. These conditions make it hostile to life as we know it.

Underground environments could be different.

If magma heats buried ice or groundwater, it might create pockets of liquid water and release chemical energy that microorganisms could potentially use.

On Earth, some microbes survive in hydrothermal environments where heat and chemical reactions provide energy without sunlight.

Scientists have suggested that comparable environments might exist beneath the Martian surface, although none has been confirmed near Alba Mons.

The newly identified fractures could therefore become interesting targets for future exploration.

Finding hydrogen chloride does not mean scientists have discovered life. It does not even establish that liquid water currently exists beneath the volcano.

Instead, the observations provide a possible explanation for how internal heat and geological activity could persist on a planet often described as dormant.

A Planet That May Be Sleeping Rather Than Dead

The ExoMars discovery demonstrates how much remains unknown about the interior of Mars.

From orbit, the planet appears dominated by ancient volcanoes, enormous canyons and dusty plains shaped by billions of years of geological history. Yet subtle chemical signals in its atmosphere may reveal processes still unfolding far below the surface.

Further observations will be needed to determine whether the hydrogen chloride truly comes from underground magma and whether similar emissions occur elsewhere.

For now, the evidence offers a compelling possibility: Mars may not have completely lost the geological energy that once shaped its surface.

The Red Planet could still be hiding a warm, active interior beneath its frozen exterior — and the clues may be escaping through cracks in the ground.

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