Minerals constitute the building blocks of rocks, and the specific minerals and their chemical compositions reveal significant insights into rock formation and history. On Mars, NASA’s dedicated rover, equipped with X-ray lithochemistry (PIXL) instruments, produces geochemical maps of rock surfaces. A recent study examined over 90,000 chemical analyses collected by PIXL during its first 1,100 days on Mars, revealing that the minerals in Jezero Crater interact with various types of liquids over time. result This will be published in Journal of Geophysics: Planets.

In this research, Eleanor Moreland, a Rice University graduate student, along with her team, utilized mineral identification through stoichiometry (MIST) algorithms to analyze PIXL data.

PIXL determines the chemical composition by bombarding Martian rocks with X-rays, yielding the most comprehensive geochemical measurements ever obtained from another planet.

“The minerals identified in Jezero Crater through MIST indicate that these volcanic rocks interacted with liquid water multiple times throughout Mars’ history, suggesting the potential for habitable conditions,” Moreland stated.

Minerals form under specific environmental conditions, such as temperature, pH, and the chemical composition of fluids, making them reliable narrators of planetary history.

Within Jezero Crater, 24 mineral species illustrate the volcanic characteristics of the Martian surface and their interactions with water over time.

Water chemically alters rocks, producing salt or clay minerals, with the specific minerals formed depending on environmental variables.

The minerals discovered in the crater showcase three different types of liquid interactions, each indicating distinct possibilities for habitability.

The first mineral suite, featuring green arilite, hizingerite, and ferroaluminoceradonite, shows localized high-temperature acidic fluids present only in crater bedrock, interpreted as among the oldest rocks studied.

The water involved in this scenario is regarded as the most conducive to life, given that research on Earth suggests high temperatures and low pH can harm biological structures.

“These hot, acidic conditions present the toughest challenges to life,” commented Kirsten Siebach, a researcher at Rice University.

“However, on Earth, life can thrive in extreme environments such as the acidic waters of Yellowstone, so this doesn’t negate the possibility of habitability.”

The second mineral suite favors more hospitable conditions and indicates a medium neutral fluid present over larger areas.

Minerals like Minnesotaite and Clinoptilolite were detected on both the crater floor and fan area, forming at lower temperatures with neutral pH, while Clinoptilolite was restricted to the crater floor.

Lastly, the third category represents a cold alkaline liquid, considered highly habitable from a modern Earth perspective.

Sepiolite, a common mineral change on Earth, was found to form under moderate temperature and alkaline conditions, widely distributed across all units explored by the rover.

The presence of sepiolite in all these units indicates multiple episodes of liquid water contributing to habitable conditions in Jezero Crater.

“These minerals demonstrate that Jezero Crater has undergone a transition from harsher, hotter, acidic liquid conditions to more neutral and alkaline environments over time.

Given that Mars samples cannot be prepared or scanned as accurately as Earth samples, the team developed an uncertainty propagation model to enhance the findings.

Using a statistical approach, MIST repeatedly assessed mineral identification while considering potential errors, analogous to how meteorologists predict hurricane paths by utilizing numerous models.

“Error analysis enables us to assign confidence levels to all mineral identifications,” Moreland remarked.

“MIST assists not just with the scientific and decision-making processes of Mars 2020, but also establishes a mineralogical archive of Jezero Crater, which will be invaluable if samples are returned to Earth.”

The findings affirm that Jezero Crater, once home to an ancient lake, has experienced a complex, dynamic aqueous history.

Each new mineral discovery brings us closer to determining whether Mars has ever supported life, while also refining strategies for sample collection and return.

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Eleanor L. Moreland et al. 2025. Multiple episodes of fluid changes in Jezero Crater indicated by the identification of MIST minerals in PIXL XRF data from the first 1100 SOL of the Mars 2020 mission. Journal of Geophysics: Planets 130 (9): e2024je008797; doi: 10.1029/2024je008797