Clues beneath Mars’ surface reveal possible habitats for ancient life

A new study has revealed tantalizing evidence of Mars’ watery past, bringing scientists a step closer to answering one of the biggest questions in planetary science: did life ever exist on the Red Planet?

Led by researchers at the Queensland University of Technology (QUT), the study focused on data from NASA’s Perseverance rover, which has been exploring Jezero Crater on Mars’ surface since its landing in 2021.

The QUT team, working alongside scientists from North America and Europe, uncovered mineral fingerprints. The footprints indicate Mars once experienced multiple periods of mineral formation – each suggesting different environmental conditions beneath the surface.

According to lead author Michael Jones, an astrophysicist at QUT, these discoveries highlight just how complex the geological history of Jezero Crater is and how many opportunities there may have been for life to take hold.

Minerals on Mars’ surface

The team’s focus was on calcium-sulfate minerals, which often form in the presence of water. These minerals were found at two sites within Jezero Crater – Hogwallow Flats and Yori Pass – in a region known as the Shenandoah formation.

“Sulphate minerals exist with different amounts of water in most regions on Mars and allow us to understand how water moved around the planet, which is key to understanding its past habitability,” explained Jones.

Until now, scientists weren’t sure how or when these minerals formed. But Jones and his colleagues introduced a novel approach to tackle this problem.

The experts adapted a new method – X-ray Backscatter Diffraction Mapping (XBDM) – originally developed at the Australian Synchrotron, to Mars-based analysis using Perseverance’s PIXL instrument. PIXL, short for Planetary Instrument for X-ray Lithochemistry, was developed by NASA with contributions from QUT alumna Abigail Allwood.

By applying XBDM to PIXL data, the team was able to probe the internal crystal structures of these minerals directly in the Martian rock. That structural fingerprint revealed the orientation and growth of the crystals, shedding light on the environmental conditions when the minerals formed.

When was life possible on Mars?

The analysis revealed two generations of calcium-sulfate crystals. One set formed just beneath the Martian surface, while the other originated from much deeper underground – at depths of at least 80 meters.

“This discovery highlights the diversity of environments that existed in the Shenandoah formation’s history – indicating multiple potential windows when life might have been possible on Mars,” Jones said.

The variation in mineral formation points to repeated cycles of subsurface water movement and geological activity, both of which are crucial in creating habitable conditions.

The broader mission of Perseverance

Since arriving in Jezero Crater, Perseverance has been exploring a variety of rock types, from ancient lava flows to the sedimentary remains of a vanished lake and river delta. The mission is driven by one of NASA’s central goals for Mars exploration: to study past environments that might have supported microbial life.

Perseverance’s samples are part of a broader campaign to collect Martian rocks and soil that may one day be returned to Earth for detailed laboratory analysis.

The rover’s findings not only help build a clearer picture of Mars’ geological evolution, but they also offer critical clues for the search for ancient biosignatures.

QUT researchers, including associate professors David  Flannery and Christoph  Schrank as well as team members Brendan Orenstein and Peter Nemere, are deeply involved in this mission through the university’s Planetary Surface Exploration Research Group.

A milestone in planetary science

The study also highlights the growing role that Australia plays in international space research. QUT’s deepening involvement with NASA and the Australian Space Agency showcases its growing influence in robotics, remote sensing, astrobiology and planetary exploration.

“Experience gained by QUT researchers exposed to the cutting edge of the robotics, automation, data science, and astrobiology fields has the potential to kick start Australia’s space industry,” said Flannery, who also serves as a long-term planner for the Perseverance mission.

The team’s innovative use of Earth-based analytical techniques on Martian data marks a milestone in planetary science. Not only does it pave the way for improved analysis of Mars’ mineral record, but it also helps sharpen the focus of future exploration efforts.

As Perseverance continues its journey across Jezero Crater on Mars’ surface, each new discovery deepens our understanding of Mars’ past. The identification of multiple mineral-forming events beneath the surface offers a compelling narrative of changing conditions – ones that might once have been just right for life.

The study is published in the journal Science Advances.

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