Bennu samples reveal a richer record of early solar-system chemistry
Studies published in January 2025 found organic molecules and salts that preserve clues to an ancient watery environment.
News report
Two studies published on January 29, 2025, reported organic compounds and salt minerals in samples returned from asteroid Bennu. The findings add direct laboratory evidence to research on chemistry in the early solar system.
NASA’s OSIRIS-REx mission delivered the material to Earth in 2023. Researchers found 14 of the 20 amino acids used by terrestrial life to build proteins and all five nucleobases used in DNA and RNA. These are chemical ingredients associated with life on Earth, not evidence that organisms lived on Bennu.
A companion mineral study identified salts consistent with evaporation of an ancient brine on Bennu’s parent body. Some of the minerals are fragile and can change after exposure to Earth’s atmosphere, making sample collection, careful storage and contamination control important to the analysis.
The studies address related questions from different directions: which organic compounds were present, and what watery environment could have affected their chemistry. The organic-matter paper also examined nitrogen-rich compounds and described evidence for reactions before and during the parent body’s history of water-related alteration.
Researchers still need to understand how such chemistry relates to the emergence of life on Earth. The results do not settle that question. They provide a better-preserved record than many meteorites, which encounter Earth’s environment before study, and give laboratories material that can be tested using multiple methods as new questions develop.
Sources
- NASA: Bennu sample reveals life-related ingredients — 2025-01-29
- Nature: An evaporite sequence from ancient brine — 2025-01-29
- Nature Astronomy: Organic matter in Bennu samples — 2025-01-29
