Mars may not be dead? ‘Smoking gun’ suggests life on Red planet

By Stephen Beech

New “smoking gun” evidence of volcanic activity on Mars suggests there could be life on the red planet, say scientists.

They believe gas seeping above volcanic rifts, detected by a European Space Agency (ESA) orbiter, suggests Mars is not geologically dead deep inside — but merely sleeping.

Fresh fissures along the Alba Mons region hint at active spots under the surface, where gases from inside the planet may be making their way up to the surface.

An international research team believes that the release of hydrogen chloride comes from hot magma beneath the surface — a sign of dormant volcanism.

The ExoMars Trace Gas Orbiter (TGO) first reported hydrogen chloride gas in the Martian atmosphere in 2021.

The gas is commonly found escaping from magmatic vents on Earth, leading researchers to wonder whether the same was happening on Mars.

Study co-leader Daniel Mège said: “Our findings suggest that Mars has retained enough internal heat to support volcanic activity until recently, and possibly still does.”

Researchers first noticed, in early summer in the northern hemisphere of Mars, spikes of hydrogen chloride where it shouldn’t have been, and during an odd season.

Mège, from the Space Research Centre of the Polish Academy of Sciences, said the gas varies seasonally on Mars, reaching its maximum in northern hemisphere winter, then mostly disappearing in the summer.

Most of the variability appears to be linked with Mars’ dust and water cycles.

But there was one exception to the pattern, always in the same season and at the same place — above volcanic fissures on the flanks of the Alba Mons volcano, in early summer.

Mars has the largest volcanoes in the solar system, but it isn’t known how active they are.

Orbital imagery shows that some volcanoes appear to have been active within the last few million years, and seismometers have detected “marsquakes” — the earthquakes of Mars.

Both facts point to the possibility of Mars being volcanically active.

However, no new lava flows or eruptions have ever been observed.

The new discovery, published in the journal Science Advances, is the result of combined atmospheric and geological analysis.

First came the detection of hydrogen chloride strongly localized in space and at a time just after the frosts of winter sublimate.

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The infrared spectrometers from TGO’s Atmospheric Chemistry Suite were on the case.

Then a close look at the Alba Mons region using TGO’s CaSSIS camera showed fresh and narrow fissures, in some cases hundreds of meters long, associated with color changes on the surface.

Mège said: “The Trace Gas Orbiter was able to find the smoking gun.

“It was like looking for a needle in a haystack.

“It’s truly amazing that it spotted a handful of molecules from a perhaps intermittent source, while moving continuously along its orbit to monitor the whole Martian atmosphere.”

Scientists suggest magmatic gases might be rising through the fissures.

Blocked by ice during winter’s freezing temperatures, down to minus 120 degrees Celsius, the fissures would channel the release of chloride as the ice sublimates in early summer.

The research team believes the discoloration around the fissures could come from deposits left behind by gases escaping from Mars’ interior.

They relied on geological intuition to make the link between the gas and the rifts.

Mège said: “Looking at the spatial distribution of the seeping, it became instantly obvious to me that there was something volcanic behind it, but it had to be demonstrated.

“A huge part of the work consisted of examining all the possible chemical processes going on in the Martian atmosphere.

“We needed to be rigorous, critical and creative to explain the presence of hydrogen chloride.

“The data were complex, but also excellent brain food.”

The team suggests that the seepage is connected to a dormant magma chamber, a type of volcanic “plumbing system” under the Martian surface.

They say magmatic gases such as hydrogen chloride could have been more abundant in the past, contributing to a thicker atmosphere and warmer climate and allowing liquid water to cover much of the Martian surface.

If lava rising through the crust meets groundwater, the researchers say it could lead to warm habitable niches.

Mège said: “Looking for Martian life in the seeping fissures of the Alba Mons region would make a lot of sense.

“If hydrothermal systems are active, they could contain the ingredients and energy needed for microorganisms to develop, and shield microorganisms from the hostile and changing environment above the surface.”

Colin Wilson, European Space Agency project scientist for the ExoMars TGO, added: “These findings may prove to be TGO’s greatest success yet.”