Meteorites, i.e., pieces of rock from outer space that have fallen to the Earth’s surface, have given researchers some clues about organic matter that was present in the early Solar System. Theses organic compounds could have served as a source for the molecules that are necessary for the emergence of life. However, meteorites are subject to contamination by the Earth’s atmosphere.
Pristine samples from asteroids, i.e., slightly larger objects that remain in space in the Solar System, can help to determine which compounds actually came from space. NASA’s “Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer” (OSIRIS-REx) mission collected pristine material from the surface of the asteroid Bennu and returned it to Earth in September 2023.
Daniel P. Glavin, NASA Goddard Space Flight Center (GSFC), Greenbelt, MD, USA, and colleagues have analyzed samples from Bennu using a range of mass spectrometry methods. The team identified a total of 33 amino acids, including 14 of the 20 canonical amino acids. They were present as racemates or near-racemic mixtures, as opposed to the L-amino acids found in living organisms on Earth. Ammonia, formaldehyde, amines, and carboxylic acids, which can serve as precursors for biomolecules, were also present. In addition, the researchers found 23 different N-heterocycles, including all five nucleobases (adenine, guanine, cytosine, thymine, and uracil).
Water-soluble nitrogen-containing compounds in the samples showed an isotopic enrichment of 15N compared with compounds from Earth, confirming their extraterrestrial origin. According to the team, asteroids such as Bennu could have been a source of nitrogen-rich compounds that acted as chemical precursors in the emergence of life on Earth.
- Abundant ammonia and nitrogen-rich soluble organic matter in samples from asteroid (101955) Bennu,
Daniel P. Glavin, Jason P. Dworkin, Conel M. O’D. Alexander, José C. Aponte, Allison A. Baczynski, Jessica J. Barnes, Hans A. Bechtel, Eve L. Berger, Aaron S. Burton, Paola Caselli, Angela H. Chung, Simon J. Clemett, George D. Cody, Gerardo Dominguez, Jamie E. Elsila, Kendra K. Farnsworth, Dionysis I. Foustoukos, Katherine H. Freeman, Yoshihiro Furukawa, Zack Gainsforth, Heather V. Graham, Tommaso Grassi, Barbara Michela Giuliano, Victoria E. Hamilton, Pierre Haenecour, Philipp R. Heck, Amy E. Hofmann, Christopher H. House, Yongsong Huang, Hannah H. Kaplan, Lindsay P. Keller, Bumsoo Kim, Toshiki Koga, Michael Liss, Hannah L. McLain, Matthew A. Marcus, Mila Matney, Timothy J. McCoy, Ophélie M. McIntosh, Angel Mojarro, Hiroshi Naraoka, Ann N. Nguyen, Michel Nuevo, Joseph A. Nuth, Yasuhiro Oba, Eric T. Parker, Tanya S. Peretyazhko, Scott A. Sandford, Ewerton Santos, Philippe Schmitt-Kopplin, Frederic Seguin, Danielle N. Simkus, Anique Shahid, Yoshinori Takano, Kathie L. Thomas-Keprta, Havishk Tripathi, Gabriella Weiss, Yuke Zheng, Nicole G. Lunning, Kevin Righter, Harold C. Connolly, Dante S. Lauretta,
Nat. Astron. 2025.
https://doi.org/10.1038/s41550-024-02472-9
