NASA's Perseverance rover has uncovered mysterious mudstones in Mars' Jezero Crater that contain organic carbon and strange mineral textures.
These features, possibly shaped by redox reactions similar to those fueled by microbes on Earth, may represent potential biosignatures.
Images and measurements from NASA's Perseverance rover indicate that recently identified rocks in Jezero Crater are composed of mudstones containing organic carbon. According to a study published in Nature, these rocks underwent chemical reactions that produced colorful and unusual textures, which may represent possible biosignatures.
The research, led by Joel Hurowitz, PhD, an Associate Professor in the Department of Geosciences at Stony Brook University, builds on studies carried out since the rover touched down in 2021. The work focuses on reconstructing Mars' early geological history and gathering samples that could eventually be transported back to Earth.
When Perseverance reached the western edge of Jezero Crater, it examined distinct mudstone outcrops in the Bright Angel formation. The Mars 2020 science team performed an in-depth geological, petrographic, and geochemical analysis, uncovering carbon material along with minerals such as ferrous iron phosphate and iron sulfide.
Although the researchers are not announcing the discovery of fossilized Martian life, they note that the rocks display features that might have been shaped by living organisms - what scientists call potential biosignatures. A potential biosignature is any element, compound, structure, or pattern that could have originated from past biological activity, but which could also arise without life. The team emphasizes that further evidence is needed before determining whether microbes played a role in forming the textures seen in these mudstones.
"These mudstones provide information about Mars' surface environmental conditions at a time hundreds of millions of years after the planet formed, and thus they can be seen as a great record of the planetary environment and habitability during that period," says Hurowitz, who has been involved with Mars rover research since he was a graduate student at Stony Brook University in 2004.
"We will need to conduct broader research into both living and non-living processes that will help us to better understand the conditions under which the collection of minerals and organic phases in the Bright Angel formation were formed," he explains.
More specifically, the researchers concluded the following during their analyses:
Continued research will be done to assess the rocks and mudstone features. For the time being, the researchers ultimately conclude that analysis of the core sample collected from this unit using high-sensitivity instrumentation on Earth will enable the measurements required to determine the origin of the minerals, organics, and textures it contains."
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Reference: "Redox-driven mineral and organic associations in Jezero Crater, Mars" by Joel A. Hurowitz, M. M. Tice, A. C. Allwood, M. L. Cable, K. P. Hand, A. E. Murphy, K. Uckert, J. F. Bell III, T. Bosak, A. P. Broz, E. Clavé, A. Cousin, S. Davidoff, E. Dehouck, K. A. Farley, S. Gupta, S.-E. Hamran, K. Hickman-Lewis, J. R. Johnson, A. J. Jones, M. W. M. Jones, P. S. Jørgensen, L. C. Kah, H. Kalucha, T. V. Kizovski, D. A. Klevang, Y. Liu, F. M. McCubbin, E. L. Moreland, G. Paar, D. A. Paige, A. C. Pascuzzo, M. S. Rice, M. E. Schmidt, K. L. Siebach, S. Siljeström, J. I. Simon, K. M. Stack, A. Steele, N. J. Tosca, A. H. Treiman, S. J. VanBommel, L. A. Wade, B. P. Weiss, R. C. Wiens, K. H. Williford, R. Barnes, P. A. Barr, A. Bechtold, P. Beck, K. Benzerara, S. Bernard, O. Beyssac, R. Bhartia, A. J. Brown, G. Caravaca, E. L. Cardarelli, E. A. Cloutis, A. G. Fairén, D. T. Flannery, T. Fornaro, T. Fouchet, B. Garczynski, F. Goméz, E. M. Hausrath, C. M. Heirwegh, C. D. K. Herd, J. E. Huggett, J. L. Jørgensen, S. W. Lee, A. Y. Li, J. N. Maki, L. Mandon, N. Mangold, J. A. Manrique, J. Martínez-Frías, J. I. Núñez, L. P. O'Neil, B. J. Orenstein, N. Phelan, C. Quantin-Nataf, P. Russell, M. D. Schulte, E. Scheller, S. Sharma, D. L. Shuster, A. Srivastava, B. V. Wogsland and Z. U. Wolf, 10 September 2025, Nature.
DOI: 10.1038/s41586-025-09413-0