Birkbeck scientist contributes to discovery of Mars rocks with possible traces of life
The Mars 2020 ‘Perseverance’ rover identified intriguing new evidence from the surface of Mars that could shed light on whether the planet was once able to support life.
Dr Keyron Hickman-Lewis, a participating scientist on NASA’s Perseverance rover mission, is co-author of a new paper in Nature reporting the discovery of Martian rocks that contain both organic carbon – a key ingredient for life – and minerals that, on Earth, are often linked to biological processes.
Since landing in February 2021, Perseverance has been exploring Jezero crater, an ancient lakebed, to study the planet’s history and collect samples for possible return to Earth. In summer 2024, it examined sedimentary rocks Neretva Vallis, the river channel leading to Jezero crater. Here, the rover found mudstones in a unit known as the Bright Angel formation, which showed an unusual combination of organic matter and minerals such as iron phosphates and sulphides.
Dr Hickman-Lewis commented:
“The identification of organic materials in association with this specific mineral assemblage is a very significant discovery. Organic materials are essential for life as we know it. Moreover, the geological context of this region of Mars, coupled with evidence for low-temperature organic–mineral reactions in water-rich conditions, suggests that we have discovered a unique habitable environment in Jezero crater.”
The Mars 2020 team has concluded that the Bright Angel formation contains a combination of textures, chemical and mineral characteristics, and organic signatures that warrant consideration as a ‘potential biosignature’. In other words, these rocks contain features that are consistent with biological processes and that, when encountered, encourage researchers to gather more data evaluate the potential presence or absence of life.
To explore further, Perseverance collected a rock sample from the Bright Angel formation, named Sapphire Canyon. While this may be one of the most promising samples yet, the rover’s instruments cannot provide all the answers.
Dr Hickman-Lewis further explained: “Sapphire Canyon is perhaps the most interesting rock sample yet collected by Perseverance and the most compelling potential evidence of life found on Mars to date. Unfortunately, we cannot unambiguously determine the origins of the organic materials and minerals within using only the instrumentation available on the rover – it is essential that we return this sample to Earth. Using high-resolution, high-sensitivity laboratory instruments, the Sapphire Canyon sample may yield answers to many outstanding questions about Mars, including whether it ever hosted life.”