Planetary scientists long viewed the fourth planet as a silent world of dormant giants, but new atmospheric measurements suggest that active volcanoes on Mars might still release underground gases. Orbiting sensors aboard the European Space Agency spacecraft detected localized plumes of hydrogen chloride rising above northern volcanic terrain, where narrow fractures cut through ice-rich ground near the broad summit of Alba Mons [1]. The observations indicate that hot molten rock could still circulate deep beneath the surface and leak volatile compounds into the atmosphere.
Unexpected Gas Signals at Alba Mons
The scientific investigation focused on hydrogen chloride (HCl), an acrid compound that escapes from volcanic vents on Earth when molten magma rises toward the crust and discharges dissolved gases into the open atmosphere [2]. On Mars, dust and sunlight also produce this gas. Chemical interactions in airborne dust normally cause concentrations to peak during the warm perihelion season, yet instruments recorded persistent plumes during aphelion, when the planet travels at its farthest orbital distance from the Sun [1]. The Atmospheric Chemistry Suite aboard the Trace Gas Orbiter cataloged eight clear detections across seventy-eight observations of the northern hemisphere [2]. Every single detection occurred within a narrow range of longitudes centered around the volcanic province of Alba Mons.
Alba Mons is the largest volcanic construct on Mars by area, spanning a gentle shield that rivals the United States in size while rising 6.8 kilometers (22,000 feet) above reference elevation [2]. Geologists dated its primary volcanic shields at 3.2 billion years. Concentrations reached roughly 1.5 parts per billion, amounting to barely two molecules per billion molecules of air.
The unusual signal demanded a detailed survey of the surrounding landscape. Researchers compared the atmospheric spikes against high-resolution orbital imagery from the CaSSIS camera on the Trace Gas Orbiter and the HiRISE camera on NASA’s Mars Reconnaissance Orbiter to pinpoint potential ground vents [2]. “These observations have been puzzling us for a long time,” said co-author Kevin Olsen of the Canadian Space Agency.
Signs of Active Volcanoes on Mars
Magma can move silently beneath solid volcanic shields. Detecting localized plumes lends weight to the theory that active volcanoes on Mars have not ceased their geological evolution, even if molten rock never breaks through the surface [3]. Researchers believe a subterranean degassing process now operates below the broad slopes of the Tharsis volcanic province [1].
Unlike Earth, where plate boundaries constantly recycle rock and vent gases into oceanic rifts, Mars functions as a single tectonic plate whose internal heat escapes through mantle plumes. NASA’s InSight lander recorded more than 1,300 marsquakes during its operational mission. Seismic recordings confirmed that the crust experiences frequent structural adjustments from internal cooling, and geologists suspect that magma movement within the lower crust generates at least a portion of those tremors [3]. On Earth, degassing systems discharge halogen gases for thousands of years after surface eruptions stop, allowing volatile elements like chlorine to filter upward through deep fractures without creating explosive ash clouds [2]. Sluggish magma bodies could easily sustain comparable releases on Mars.
Earlier surveys noted that volcanic activity could endure far longer than standard planetary timelines suggested. Our previous analysis of recent volcanic eruptions on Mars outlined young basaltic features that formed in recent epochs across Cerberus Fossae. Tracking atmospheric hydrogen chloride provides direct empirical evidence of volatile release occurring in real time above active geological structures [1].
Narrow Surface Fissures Beneath the Plumes
Orbital cameras pointed toward the gas coordinates uncovered intricate networks of narrow ground fractures cutting through the rugged volcanic plains that slope gently northward from the caldera of Alba Mons [2]. Some fractures measured only tens of centimeters wide. Other fissures extended along elevated ridges for several kilometers, showing clean, crisp boundaries that indicate minimal erosion from dust storms or wind-driven sand [1]. These fractures cut across ice-cemented mantle units thought to be hundreds of thousands of years old. Their narrow profiles suggest that the fissures formed recently in geological time, because surface dust would quickly fill static crevices on the windswept surface.
Their youthful appearance implies ongoing mechanical deformation within the crust. Dark patches line sections of the fracture walls, pointing to possible mineral deposition around venting fissures. “The Trace Gas Orbiter was able to find the smoking gun,” said co-lead author Daniel Mège of the Polish Academy of Sciences [3]. He noted that orbital instruments detected molecules from intermittent vents.
Deep magma provides the pressure to crack rock. The research team mapped the alignment of these fractures against regional fault lines surrounding the Tharsis volcanic bulge. The cracks match structural fault lines shaped by magma chambers deep below Alba Mons, suggesting that the fissures serve as open vents connecting deep thermal reservoirs with the atmosphere [1].
Seasonal Ice and Gas Trapping
During colder months, water ice crystals absorb floating molecules of gas. The timing of the detections created a puzzle because hydrogen chloride typically attaches to airborne dust and water droplets, falling from the atmosphere as winter frost covers the hemisphere [3]. Yet the Atmospheric Chemistry Suite recorded distinct concentrations of hydrogen chloride above Alba Mons specifically during the cold aphelion season [1].
To explain this anomaly, the study published in Science Advances proposes an icy buffer model where a subsurface layer of permafrost traps volcanic gases rising through deep rock fissures during the long Martian winter [1]. Ground ice prevents volatile gases from reaching the air. When early summer sunshine warms the surface, ice sublimates into water vapor without melting into liquid, unblocking the narrow fissures and venting trapped hydrogen chloride into the lower atmosphere [2]. This seasonal release explains why the orbital spacecraft observed the gas only during specific periods over Alba Mons. The mechanism shows how local ground conditions can modulate volcanic emissions on worlds where sub-zero temperatures dominate the surface environment for months at a time [3]. Subsurface ice acts as a temporary seal before solar warmth releases the gas.
Searching Active Volcanoes on Mars for Life
Internal planetary heat changes the biological equation. The discovery that active volcanoes on Mars could still feed gas through open surface fractures carries significant consequences for astrobiology and the search for extraterrestrial microbial habitats [3]. Underground hydrothermal channels would protect delicate chemical processes from lethal cosmic radiation and extreme temperature swings on the surface.
If rising magma bodies heat buried ice deposits in the crust, the interaction could establish stable hydrothermal systems with circulating mineral-rich fluids, similar to volcanic springs that support deep microbial ecosystems on Earth [2]. While robotic rovers focus on sedimentary rocks during the search for life on the Martian surface, volcanic fissures present an entirely different target for future exploratory landers. “Looking for Martian life in the seeping fissures of the Alba Mons region would make a lot of sense,” Mège said [3]. He explained that hydrothermal environments supply chemical energy and dissolved nutrients that allow microorganisms to thrive without direct sunlight [2]. Liquid water has not been detected beneath Alba Mons, but heat and chemical gases keep scientific interest high.
The Evolving Picture of Martian Interior Heat
Earth recycles chlorine through continuous plate subduction and volcanism. The new data sheds light on the broader chlorine cycle that began when primordial volcanoes first degassed volatile elements during planetary accretion billions of years ago [1]. Without plate tectonics to bury and melt surface minerals, Mars must rely on localized magma chambers to inject fresh halogen gases back into its thin atmosphere [3].
These gas readings combine with seismic recordings and young volcanic deposits to replace the assumption of a completely frozen world with a model of intermittent activity [2]. Mars is neither dead nor violently erupting. Instead, pools of magma appear to cool gradually miles below the crust, venting trace gases through surface cracks while retaining enough thermal energy to influence local geology [3]. Future orbital missions will monitor northern volcanic zones to see if other halogen plumes emerge. As researchers refine their atmospheric instruments, every new trace of volcanic gas helps map the hidden fires that still burn inside the Red Planet [1]. Lingering interior warmth reminds scientists that planetary evolution unfolds over immense spans of time.
- ACADEMIC JOURNAL Trokhimovskiy, A., Mège, D., Korablev, O., Olsen, K. S., Fedorova, A. A., Taysum, B., Tesson, P., Luginin, M., Montmessin, F., Vlasov, P., Grigoriev, A., Alday, J., Belyaev, D., Ignatiev, N., Patrakeev, A., Kokonkov, N., Ivanov, Y., Gurgurewicz, J., Pommerol, A., & Thomas, N. (2026). Enigmatic HCl detections as a potential signature of igneous activity on Mars. Science Advances, 12(45). [Article Link]
- ONLINE NEWS Andrei, M. (2026, November 6). Scientists found a strange gas leaking from Mars and it may come from its volcanoes. ZME Science. [Article Link]
- ONLINE NEWS Anderson, P. S. (2026, November 6). Active volcanoes on Mars? Noxious gas discovery says — maybe. EarthSky. [Article Link]
APA 7: PerEXP Teamworks. (2026, November 7). Alba Mons Gas Detections Suggest Active Volcanoes on Mars. PerEXP Teamworks. https://perexpteamworks.com/en/active-volcanoes-on-mars-gas-study/
