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What a smelly gas leaking from Mars tells us about its volcanoes

a full image of mars.NASA/JPL/MSSS

Mars is also known as the Red Planet because of the red dust that covers its surface

Scientists have long been looking for life outside of Earth.

Mars - one of our closest neighbours - has been the focus of a lot of their research.

Now the European Space Agency (ESA) has discovered that some volcanoes on the surface of the Red Planet might be more active than first thought.

And with that discovery could be a new chance of finding life existing beneath Mars' surface.

Mars could have supported life at one point and a new rover could be the key to finding out more (from October 2025)

Very small amounts of a chemical called hydrogen chloride have been detected by the ESA's ExoMars Trace Gas Orbiter.

Hydrogen chloride is a smelly gas, with a scent similar to very strong vinegar.

It is found escaping from openings in the Earth's crust.

Scientists think this could mean an area of Mars called Alba Mons might have active or had recently active volcanoes - though they can't be sure.

"Our findings suggest that Mars has retained enough internal heat to support volcanic activity until recently and possibly still does," said Professor Daniel Mège, co-lead author of the study.

illustration shows a full image of Mars including its north pole and then an inset image that shows the surface height of the area near alba mons. below the inset is a measurement key which shows the height by colour and finally in the top right hand corner is the european space agency logo.ESA/DLR/FU

The image shows the location on Mars where the hydrogen chloride has been detected

Not only have spikes in hydrogen chloride been found near Alba Mons, but marsquakes have also been detected across the planet.

The ESA's Trace Gas Orbiter also found new breaks in Mars's crust - known as fissures - in the area.

"It was like looking for a needle in a haystack," says Professor Mège.

And not only does the evidence of possible volcanic activity on Mars excite scientists, it could also point to another potential discovery.

"Looking for Martian life in the seeping fissures of the Alba Mons region would make a lot of sense," says Professor Mège.

"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."