Evidence of Hexagonal Patterns on Mars: Indications of a Climate Suitable for Life’s Development

A pattern of hexagonal fossils in sedimentary rocks has been analyzed by Curiosity on its 3154th day of exploration in Gale Crater on Mars. Photo: NASA/JPL-Caltech/MSSS/IRAP/Rapin et al./Nature

Mars has revealed fossil evidence of a climate with alternating wet and dry seasons, similar to Earth’s climate. Such an environment, where simple organic molecules have been found, could have offered optimal conditions for the creation of complex organic materials. This discovery provides new avenues for examining the processes that led to life, traces of which no longer exist on Earth.

Data collected by NASA’s Curiosity rover has allowed scientists to identify patterns on Mars that indicate a seasonal climate analogous to Earth’s. This groundbreaking find offers new directions for exploring the origins of life.

The study, carried out by researchers at CNRS, Université Toulouse III – Paul Sabatier, Université Claude Bernard Lyon 1, and including CNES, was published in Nature on August 9, 2023.

Mars’s Landscape and Prior Discoveries

Unlike Earth, Mars’s surface isn’t constantly refreshed by plate tectonics, preserving large areas notable for their fossilized rivers and lakes from billions of years ago. Since 2012, NASA’s Curiosity, the first to investigate these ancient remnants, has detected simple organic molecules, which can result from both geological and biological means.

Requirements for Life Emergence

The inception of early life forms, as speculated by scientists, needs an environment that encourages the transformation of these simple molecules into intricate organic compounds. A research team from the Institut de Recherche en Astrophysique et Planétologie and the Laboratoire de Géologie: Terre, Planètes, Environnement, along with North American colleagues, has found these exact conditions.

Martian Climate Patterns: Evidence

Using Curiosity’s Mastcam and ChemCam, scientists uncovered salt deposits forming a hexagonal pattern in sedimentary layers from 3.8 to 3.6 billion years ago. Resembling hexagons found in Earth’s seasonally drying basins, this is the first fossilized evidence of a consistent, cyclical Martian climate with distinct dry and wet periods. Laboratory tests have demonstrated that this environment allows for ideal interactions leading to the creation of complex life-forming compounds, such as RNA.

Conclusion: New Avenues for Research

These recent observations will allow a renewed examination of large-scale images obtained from orbit, highlighting terrains with similar makeup. Scientists now know where to search for signs of natural processes that birthed life, the traces of which are no longer present on Earth.

This conceptual illustration displays NASA’s Mars Science Laboratory Curiosity rover, a mobile robot that probes Mars’s ability to support microbial life, past or present. Credit: NASA/JPL-Caltech

NASA’s Curiosity Rover

NASA’s Curiosity Rover, a vehicle-sized robotic explorer, has been examining the Gale Crater on Mars since landing on August 6, 2012. As a key part of NASA’s Mars Science Laboratory (MSL) mission, its primary mission is to assess if Mars ever possessed the necessary conditions for microbial life. It boasts various tools for groundbreaking Martian surface research.

The Mastcam, an essential tool on Curiosity, includes two camera systems on the rover’s “mast,” offering an excellent viewpoint for observing Martian geology.

The ChemCam consists of a series of remote-sensing tools, encompassing a camera, laser, and spectrometer, designed to scrutinize the chemical composition of Martian rocks and soil.

Collectively, the Mastcam and ChemCam give scientists an unparalleled ability to probe Mars’s geology and possible habitability, rendering detailed visual and chemical insights.

Reference: “Sustained wet–dry cycling on early Mars” by W. Rapin, G. Dromart, B. C. Clark, J. Schieber, E. S. Kite, L. C. Kah, L. M. Thompson, O. Gasnault, J. Lasue, P.-Y. Meslin, P. J. Gasda and N. L. Lanza, 9 August 2023, Nature.
DOI: 10.1038/s41586-023-06220-3

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More about fokus keyword: Mars

• NASA’s Mars Science Laboratory
• Nature Journal
• CNRS (Centre National de la Recherche Scientifique)
• Université Toulouse III – Paul Sabatier
• Université Claude Bernard Lyon 1