At a Glance
- NASA’s Curiosity rover found evidence of a carbon cycle on ancient Mars, uncovering siderite in sulfate-rich layers of Mount Sharp. This suggests that the planet may have supported life in the past.
- Siderite, a mineral formed in CO2-rich environments, indicates that Mars once had a CO2-dominated atmosphere capable of sustaining liquid water, suggesting a significant climate transition from wet to dry conditions.
- The study shows that Mars had a more habitable climate in the past, with liquid water on the surface. Scientists are investigating other Martian regions for similar mineral deposits to further understand Mars’s history.
- The findings provide valuable insights for Earth scientists. Studying carbon sequestration on Mars could inform climate change mitigation efforts and explain how similar processes might help manage CO2 on Earth.
- Understanding Mars’ climate shifts and the role of CO2 in its habitability highlights the fragility of planetary environments and offers lessons for preserving Earth’s habitability in the face of climate change.
NASA’s Curiosity rover has uncovered significant evidence of a carbon cycle on ancient Mars, which could provide insight into whether the planet could ever support life. A team of researchers, led by Dr. Ben Tutolo from the University of Calgary, analyzed data collected by Curiosity from Gale Crater. Their findings, published in Science (1, 2), revealed traces of siderite, an iron carbonate, embedded in sulfate-rich layers of Mount Sharp. This discovery could help scientists understand how Mars’ atmosphere and climate evolved.
Siderite, a mineral that forms in environments with high levels of carbon dioxide (CO2), suggests Mars once had a CO2-rich atmosphere capable of sustaining liquid water. The presence of siderite also implies that the planet underwent a significant climate transition, shifting from a warm and wet environment to the cold and dry conditions seen today. This change may have been driven by the sequestration of CO2 into rock, with the carbonates forming as the atmosphere thinned.
The study reveals that the Martian climate was likely much more habitable in the past, supporting liquid water on the surface. As Curiosity continues to explore Gale Crater, scientists are also studying other regions of Mars for similar mineral deposits that could offer more clues about the planet’s early history. Dr. Tutolo and his team believe that understanding these processes could help us better understand how Mars transitioned from a potentially habitable planet to one that is now inhospitable.
The findings are also relevant for Earth scientists, as they parallel efforts to mitigate climate change. Tutolo noted that studying the mechanisms of carbon sequestration on Mars could offer insights into how humans might use similar processes to manage CO2 on Earth. “Learning from Mars shows us how fragile habitability can be,” he said. Understanding how small changes in CO2 affect Mars may help us protect Earth’s habitability for the future.
References
- University of Calgary. (April 17). Curiosity rover finds large carbon deposits on Mars. Phys.Org; University of Calgary. https://phys.org/news/2025-04-curiosity-rover-large-carbon-deposits.html
- Bishop, J. L., & Lane, M. D. (2025). Catching a glimpse of ancient Mars. Science, 388(6744), 251–252. https://doi.org/10.1126/science.adw4889
- Tutolo, B. M., Hausrath, E. M., Kite, E. S., Rampe, E. B., Bristow, T. F., Downs, R. T., Treiman, A., Peretyazhko, T. S., Thorpe, M. T., Grotzinger, J. P., Roberts, A. L., Archer, P. D., Des Marais, D. J., Blake, D. F., Vaniman, D. T., Morrison, S. M., Chipera, S., Hazen, R. M., Morris, R. V., … Vasavada, A. R. (2025). Carbonates identified by the Curiosity rover indicate a carbon cycle operated on ancient Mars. Science, 388(6744), 292–297. https://doi.org/10.1126/science.ado9966
