Mars is not geologically dead deep inside, but merely sleeping. Recent cracks throughout the Alba Mons region hint at subsurface thermal zones, allowing interior planetary gases to ascend upward.
An international research team led by Alexander Trokhimovskiy suggests that the release of hydrogen chloride comes from hot magma beneath the surface. This points directly to dormant volcanism. The ExoMars Trace Gas Orbiter first reported hydrogen chloride gas in the martian atmosphere back in 2021.
Gas varies seasonally on Mars, reaching its maximum in northern hemisphere winter before mostly disappearing in the summer.
Researchers recorded anomalous spikes along the flanks of Alba Mons in the Tharsis region, roughly 2,400 kilometers from Olympus Mons, according to source material. A targeted search revealed a total of six spikes, comprising four instances situated between latitudes of 55°N and 66°N alongside two detections from 43°N to 48°N. All detections fell within a narrow longitude band from 96°W to 117°W just after seasonal frosts sublimated.
Scientists used the Atmospheric Chemistry Suite on ESA’s Trace Gas Orbiter to detect hydrogen chloride at parts-per-billion levels. Researchers also examined high-resolution images from the HiRISE, CaSSIS, and CTX cameras. They identified narrow fissures, some tens of centimeters wide and forming swarms tens of kilometers long on topographic ridges.
The team proposes that such fractures serve as pathways for hydrogen chloride rising from magmatic bodies at depth. Assuming an atmospheric lifetime of one sol for hydrogen chloride, authors estimate a seepage rate of less than 3 kilograms per second.
Our findings suggest that Mars has retained enough internal heat to support volcanic activity until recently, and possibly still does,
said Daniel Mège, co-lead author of a paper published in Science Advances.
The Trace Gas Orbiter was able to find the smoking gun,
Mège added. The study itself was published in Science Advances, according to Space.
If rising lava meets groundwater, this process could create warm habitable niches. Mège noted that looking for martian life in the seeping fissures of the Alba Mons region makes a lot of sense if hydrothermal systems are active.
Colin Wilson, ESA’s project scientist for the ExoMars Trace Gas Orbiter, highlighted that these findings may prove to be the orbiter’s greatest success yet. While orbital imagery shows volcanoes active within the last few million years and seismometers detect marsquakes, no new lava flows or eruptions have ever been observed.
- How much hydrogen chloride seeps from the fissures?
- Researchers estimate a seepage rate of less than 3 kilograms per second, which compares to the low end of fluxes at terrestrial volcanoes.
- When did the Trace Gas Orbiter first spot the gas?
- The TGO first reported hydrogen chloride gas in the martian atmosphere back in 2021 before making targeted detections over Alba Mons.
- Where are the newly found fissures located?
- The narrow fractures sit on the flanks of Alba Mons in the Tharsis region within a narrow longitude band from 96°W to 117°W.
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