Bennu Sample Reveals Diverse Chemical Landscape Shaped by Ancient Water

Nanoscale scans of asteroid Bennu uncover three distinct organic-mineral domains, reshaping understanding of early Solar System processes.

Mar. 30, 2026 at 9:50pm

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A highly structured abstract painting in soft, earthy tones of ochre, sienna, and sage green, depicting sweeping geometric arcs, concentric planetary circles, and precise botanical spirals, conceptually representing the complex chemical composition and structural order of materials from the early Solar System.Nanoscale analysis of a Bennu asteroid sample reveals a diverse chemical landscape shaped by ancient water, providing new insights into the early Solar System.Stony Brook University Today

A study analyzing samples from the asteroid Bennu collected by NASA's OSIRIS-REx mission has revealed a diverse chemical landscape shaped by ancient water. The research team at Stony Brook University found that the Bennu samples contain three chemically distinct organic-mineral domains, indicating that liquid water altered the asteroid through different interactions at various locations rather than a uniform process. These findings provide new insights into how minerals, water, and organic matter interacted in the early Solar System and have implications for understanding the delivery of prebiotic chemistry to early Earth.

Why it matters

Asteroid Bennu is considered one of the best-preserved remnants of the early Solar System, making the samples collected by OSIRIS-REx invaluable for studying the chemical processes and interactions that occurred during the formation of our planetary system. These new findings shed light on how organic materials, water, and minerals coexisted and were altered on primitive solar system bodies, which has direct relevance for understanding the origins of prebiotic chemistry and the potential for life.

The details

The research team used nanoscale infrared and Raman spectroscopy to analyze a Bennu sample called OREX-800066-3, which was collected and returned to Earth by the OSIRIS-REx mission in September 2023. The analysis revealed that at the nanoscale, the distribution of Bennu's minerals and organic matter was not uniform, but rather occurred in three chemically distinct and recurring organic-mineral domains. One domain was rich in carbonate minerals, another was rich in aliphatic organic compounds, and the third was rich in nitrogen-containing organic compounds. These results suggest that liquid water altered Bennu through different interactions at various locations, rather than by a uniform process.

  • The OSIRIS-REx mission collected the Bennu sample OREX-800066-3 in September 2023.
  • The research team at Stony Brook University analyzed the Bennu sample and published their findings in the Proceedings of the National Academy of Sciences (PNAS) in March 2026.

The players

Mehmet Yesiltas

A professor at Stony Brook University who led the research team that analyzed the Bennu sample.

NASA's OSIRIS-REx mission

The NASA mission that collected the Bennu sample OREX-800066-3 and returned it to Earth in September 2023.

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What they’re saying

“These findings carry broader significance for planetary science and astrobiology.”

— Mehmet Yesiltas, Professor, Stony Brook University

“The findings demonstrate survival of chemically labile, nitrogen-bearing organics through aqueous alteration on a small solar system body has direct implications for long-standing questions about how organic complexity is built up and preserved in primitive planetary materials.”

— Mehmet Yesiltas, Professor, Stony Brook University

“By extension, it may reveal how organics relevant to prebiotic chemistry may have been delivered to early Earth via carbonaceous asteroids and may have played a role in the chemical processes that might have eventually led to life.”

— Mehmet Yesiltas, Professor, Stony Brook University

What’s next

The research team plans to continue analyzing the Bennu samples returned by the OSIRIS-REx mission to further understand the chemical and geological history of this primitive asteroid and its implications for the early Solar System.

The takeaway

The diverse chemical landscape of asteroid Bennu revealed by this study provides new insights into how organic materials, water, and minerals interacted and were altered on primitive solar system bodies, reshaping our understanding of the processes that may have contributed to the origins of life on Earth.