Periodic Reporting for period 4 - MarsFirstWater (The physicochemical nature of water on early Mars)
Berichtszeitraum: 2023-12-01 bis 2024-11-30
Mars is the only known planetary body, other than Earth, where liquid water appears to have played a key role in its early surface evolution. However, details regarding the physicochemical nature of water and its early evolution, on both global and local scales, whether liquid or solid H2O dominated, for what duration of time, when and where, what were the host-rock weathering rates and patterns and the physicochemical parameters defining such interactions, what specific landforms and mineralogies were generated during those periods, and what implications all these processes had on the possible development of life on Mars, are still poorly developed. Many fundamental questions about aqueous processes on early Mars are still in the need of answers.
The overall objective of this investigation was to fully characterize the physicochemical nature of water on early Mars through a quantitative and truly interdisciplinary investigation. We developed several innovative strategies in 4 main lines: geomorphological analysis, geochemical modeling, mineralogical studies and astrobiological investigations. Our results have filled existing gaps in our knowledge of early Mars, producing hard constraints on the physicochemical nature of water early in the history of the planet. This was a truly interdisciplinary Project: the 4 main lines of investigation were intimately interrelated among them, and the results produced as tasks evolved fed other research areas in a continuous internal synergy.
The results of this investigation will prove a pathfinder for other investigators’ qualitative and quantitative analyses of Martian hydrogeology, geochemistry and mineralogy, computer modelling, microbiology, and robotic mission operations and data analysis, providing opportunities to opening new paths for in situ exploration by landers and rovers.
The overall objective of this investigation was to fully characterize the physicochemical nature of water on early Mars through a quantitative and truly interdisciplinary investigation. We developed several innovative strategies in 4 main lines: geomorphological analysis, geochemical modeling, mineralogical studies and astrobiological investigations. Our results have filled existing gaps in our knowledge of early Mars, producing hard constraints on the physicochemical nature of water early in the history of the planet. This was a truly interdisciplinary Project: the 4 main lines of investigation were intimately interrelated among them, and the results produced as tasks evolved fed other research areas in a continuous internal synergy.
The results of this investigation will prove a pathfinder for other investigators’ qualitative and quantitative analyses of Martian hydrogeology, geochemistry and mineralogy, computer modelling, microbiology, and robotic mission operations and data analysis, providing opportunities to opening new paths for in situ exploration by landers and rovers.
The work was organized in 4 Research Themes (RTs). Major scientific developments have included, in each RT:
• RT1, Geology: Publication of a new geomorphological map of the Sinus Sabaeus region of Mars, a basis for identifying the ancient presence of water in the region. First identification of rythmites on Mars, verifying that impact events were a major source for liquid water on early Mars. Documentation of the history of one specific aqueous episode on early Mars, providing first evidence for powerful storms, torrential rains, megafloods, and strong waves in a martian paleolake. Calculation of the volume of water accumulated on the Martian lowlands, using the early Noachian crater distribution.
• RT2, Geochemistry: Analysis of the reactivity of pyrite to ferric oxides and sulfate minerals under present and early Martian surface conditions, explaining the scarcity of disulfide deposits on the Martian surface. Reconstruction of the environmental conditions that facilitated iron oxidation during the anoxic and iron-rich Archean conditions, to better understand the connection between iron mineralogy and the formation of carbonate minerals on Mars. Quantification of how past fluids on Mars interacted with and altered the surface, depending on fluid pH, and how this alteration modified the preservation potential of organic matter embedded in clay minerals.
• RT3, Mineralogy: First identification of glauconite minerals on Mars using in situ data from the Curiosity rover, contributing to clarify the formation of clays on early Mars. First identification of a subsoil wet clay layer in the hyperarid core of the Atacama Desert, harvesting new data to help determine the preferred mineral sequences where to look for biosignatures in the Martian subsurface. Development of a statistical mass-balance calculation procedure to narrow the range of chemical composition of the clay minerals and amorphous phases observed in Mars, providing the basis for their identification and subsequent interpretation of their formation environment.
• RT4, Geomicrobiology and Astrobiology: Using a novel methodology, µ-DSC, identification of the ability of microorganisms to change the freezing/melting curve of cold salty solutions, expressing proteins that can affect the liquid-to-ice transition. Contribution of a new instrument concept to search for evidences of an ancient biosphere on Mars. Investigations in 4 Mars bioanalogs. (1) The Atacama Desert, deciphering the dispersion of microbial life using dust transported by wind, proposing the term “dark biosphere” referred to microorganisms with a high rate of phylogenetic indeterminacy, and deciphering the metabolic strategies available to potential martian microorganisms during their adaptation to water stress. (2) Antarctica, describing the geomicrobiology of the permanently exposed lithic substrates of nunataks. (3) Rio Tinto, characterizing the microbial diversity existing in the deep subsurface of the Iberian Pyrite Belt. And (4) Tirez Lake, describing the evolution of the microbial communities during desiccation of the endorheic hypersaline lagoon, and proposing the concept of “astrobiological time-analogs”, referred to terrestrial analogs that can help understand environmental transitions and the related possible ecological successions on early Mars.
Our work has generated 49 peer-reviewed scientific papers, 69 meeting communications, a dozen of press releases, another dozen of press inquiries, and 3 tailored dissemination pieces.
• RT1, Geology: Publication of a new geomorphological map of the Sinus Sabaeus region of Mars, a basis for identifying the ancient presence of water in the region. First identification of rythmites on Mars, verifying that impact events were a major source for liquid water on early Mars. Documentation of the history of one specific aqueous episode on early Mars, providing first evidence for powerful storms, torrential rains, megafloods, and strong waves in a martian paleolake. Calculation of the volume of water accumulated on the Martian lowlands, using the early Noachian crater distribution.
• RT2, Geochemistry: Analysis of the reactivity of pyrite to ferric oxides and sulfate minerals under present and early Martian surface conditions, explaining the scarcity of disulfide deposits on the Martian surface. Reconstruction of the environmental conditions that facilitated iron oxidation during the anoxic and iron-rich Archean conditions, to better understand the connection between iron mineralogy and the formation of carbonate minerals on Mars. Quantification of how past fluids on Mars interacted with and altered the surface, depending on fluid pH, and how this alteration modified the preservation potential of organic matter embedded in clay minerals.
• RT3, Mineralogy: First identification of glauconite minerals on Mars using in situ data from the Curiosity rover, contributing to clarify the formation of clays on early Mars. First identification of a subsoil wet clay layer in the hyperarid core of the Atacama Desert, harvesting new data to help determine the preferred mineral sequences where to look for biosignatures in the Martian subsurface. Development of a statistical mass-balance calculation procedure to narrow the range of chemical composition of the clay minerals and amorphous phases observed in Mars, providing the basis for their identification and subsequent interpretation of their formation environment.
• RT4, Geomicrobiology and Astrobiology: Using a novel methodology, µ-DSC, identification of the ability of microorganisms to change the freezing/melting curve of cold salty solutions, expressing proteins that can affect the liquid-to-ice transition. Contribution of a new instrument concept to search for evidences of an ancient biosphere on Mars. Investigations in 4 Mars bioanalogs. (1) The Atacama Desert, deciphering the dispersion of microbial life using dust transported by wind, proposing the term “dark biosphere” referred to microorganisms with a high rate of phylogenetic indeterminacy, and deciphering the metabolic strategies available to potential martian microorganisms during their adaptation to water stress. (2) Antarctica, describing the geomicrobiology of the permanently exposed lithic substrates of nunataks. (3) Rio Tinto, characterizing the microbial diversity existing in the deep subsurface of the Iberian Pyrite Belt. And (4) Tirez Lake, describing the evolution of the microbial communities during desiccation of the endorheic hypersaline lagoon, and proposing the concept of “astrobiological time-analogs”, referred to terrestrial analogs that can help understand environmental transitions and the related possible ecological successions on early Mars.
Our work has generated 49 peer-reviewed scientific papers, 69 meeting communications, a dozen of press releases, another dozen of press inquiries, and 3 tailored dissemination pieces.
Most significant advances:
1- A novel map of water and water ice during the Noachian near the Martian dichotomy.
2- New quantification of the thickness and volume of the stratigraphic sequence of volcanic infilling of the Martian lowlands.
3- First identification of rythmites on Mars.
4- Explanation of the paucity of disulfide deposits on the Martian surface, by analyzing of the reactivity of pyrite to ferric oxides and sulfate minerals under present and early Martian surface conditions.
5- Identification of one of the earliest intervals of oxygen accumulation on Earth, predating previous estimates of the first accumulation of atmospheric oxygen by ∼500 Ma.
6- Identification of the environmental conditions that facilitated iron oxidation during the anoxic and iron-rich Archean conditions, as an early Mars analog.
7- Application of our previously developed dynamic model of Li-isotope fractionation during silicate weathering under Martian conditions to a representative bedrock composition in Gale crater, to understand the geochemical evolution of hydrated minerals on early Mars.
8- First detection of glauconites on Mars.
9- Discovery of subsurface wet and inhabited clays in Atacama as analogs to the Martian subsoil.
10- First quantification of the effect of fluid pH on the ability of clays to preserve organics.
11- First quantification of sensitivity limits of biosignature-detection instruments landed on Mars.
12- Identification of a metabolic pathway by which microorganisms may increase the habitability of cold salty solutions.
13- Characterization of representative microbial model species from cold environments, in order to understand how life was able to adapt to the desiccation stress induced by freezing, as a model for possible inhabited environments on early Mars.
14- Introduction of the new concepts “dark biosphere” and “astrobiological time-analog”.
15- Proposal of a new astrobiological instrument to search for biomarkers on Mars (our paper describing this instrument received the “EANA 2021 Outstanding Paper Award”).
1- A novel map of water and water ice during the Noachian near the Martian dichotomy.
2- New quantification of the thickness and volume of the stratigraphic sequence of volcanic infilling of the Martian lowlands.
3- First identification of rythmites on Mars.
4- Explanation of the paucity of disulfide deposits on the Martian surface, by analyzing of the reactivity of pyrite to ferric oxides and sulfate minerals under present and early Martian surface conditions.
5- Identification of one of the earliest intervals of oxygen accumulation on Earth, predating previous estimates of the first accumulation of atmospheric oxygen by ∼500 Ma.
6- Identification of the environmental conditions that facilitated iron oxidation during the anoxic and iron-rich Archean conditions, as an early Mars analog.
7- Application of our previously developed dynamic model of Li-isotope fractionation during silicate weathering under Martian conditions to a representative bedrock composition in Gale crater, to understand the geochemical evolution of hydrated minerals on early Mars.
8- First detection of glauconites on Mars.
9- Discovery of subsurface wet and inhabited clays in Atacama as analogs to the Martian subsoil.
10- First quantification of the effect of fluid pH on the ability of clays to preserve organics.
11- First quantification of sensitivity limits of biosignature-detection instruments landed on Mars.
12- Identification of a metabolic pathway by which microorganisms may increase the habitability of cold salty solutions.
13- Characterization of representative microbial model species from cold environments, in order to understand how life was able to adapt to the desiccation stress induced by freezing, as a model for possible inhabited environments on early Mars.
14- Introduction of the new concepts “dark biosphere” and “astrobiological time-analog”.
15- Proposal of a new astrobiological instrument to search for biomarkers on Mars (our paper describing this instrument received the “EANA 2021 Outstanding Paper Award”).