Abundant ammonia and nitrogen-rich soluble organic matter in samples from asteroid (101955) Bennu

Journal Article · Wed Jan 29 00:00:00 EST 2025 · Nature Astronomy

DOI:https://doi.org/10.1038/s41550-024-02472-9· OSTI ID:2531215

Glavin, Daniel P. ^[1]; Dworkin, Jason P.; Alexander, Conel O’D.; Aponte, José C.; Baczynski, Allison A.; Barnes, Jessica J.; Bechtel, Hans A.; Berger, Eve L.; Burton, Aaron S.; Caselli, Paola; Chung, Angela H.; Clemett, Simon J.; Cody, George D.; Dominguez, Gerardo; Elsila, Jamie E.; Farnsworth, Kendra K.; Foustoukos, Dionysis I.; Freeman, Katherine H.; Furukawa, Yoshihiro; Gainsforth, Zack ; Graham, Heather V.; Grassi, Tommaso; Giuliano, Barbara Michela; Hamilton, Victoria E.; Haenecour, Pierre; Heck, Philipp R.; Hofmann, Amy E.; House, Christopher H.; Huang, Yongsong; Kaplan, Hannah H.; Keller, Lindsay P.; Kim, Bumsoo; Koga, Toshiki; Liss, Michael; McLain, Hannah L.; Marcus, Matthew A.; Matney, Mila; McCoy, Timothy J.; McIntosh, Ophélie M.; Mojarro, Angel; Naraoka, Hiroshi; Nguyen, Ann N.; Nuevo, Michel; Nuth, Joseph A.; Oba, Yasuhiro; Parker, Eric T.; Peretyazhko, Tanya S.; Sandford, Scott A.; Santos, Ewerton; Schmitt-Kopplin, Philippe; Seguin, Frederic; Simkus, Danielle N.; Shahid, Anique; Takano, Yoshinori; Thomas-Keprta, Kathie L.; Tripathi, Havishk; Weiss, Gabriella; Zheng, Yuke; Lunning, Nicole G.; Righter, Kevin; Connolly, Harold C.; Lauretta, Dante S.

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1. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); et al.

Organic matter in meteorites reveals clues about early Solar System chemistry and the origin of molecules important to life, but terrestrial exposure complicates interpretation. Samples returned from the B-type asteroid Bennu by the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer mission enabled us to study pristine carbonaceous astromaterial without uncontrolled exposure to Earth’s biosphere. Here we show that Bennu samples are volatile rich, with more carbon, nitrogen and ammonia than samples from asteroid Ryugu and most meteorites. Nitrogen-15 isotopic enrichments indicate that ammonia and other N-containing soluble molecules formed in a cold molecular cloud or the outer protoplanetary disk. We detected amino acids (including 14 of the 20 used in terrestrial biology), amines, formaldehyde, carboxylic acids, polycyclic aromatic hydrocarbons and N-heterocycles (including all five nucleobases found in DNA and RNA), along with ~10,000 N-bearing chemical species. All chiral non-protein amino acids were racemic or nearly so, implying that terrestrial life’s left-handed chirality may not be due to bias in prebiotic molecules delivered by impacts. The relative abundances of amino acids and other soluble organics suggest formation and alteration by low-temperature reactions, possibly in NH₃-rich fluids. Bennu’s parent asteroid developed in or accreted ices from a reservoir in the outer Solar System where ammonia ice was stable.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Molecular Foundry
• Sponsoring Organization: National Aeronautics and Space Administration (NASA); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 2531215
• Journal Information: Nature Astronomy, Journal Name: Nature Astronomy Journal Issue: 2 Vol. 9; ISSN 2397-3366
• Publisher: Springer Nature
• Country of Publication: United States
• Language: English

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79 ASTRONOMY AND ASTROPHYSICS