Astrochemistry

Nitrogen- And Oxygen-Rich Organic Material Indicative Of Polymerization In Pre-aqueous Cryochemistry On Bennu’s Parent Body

By Keith Cowing

Status Report

Nature via PubMed

December 21, 2025

Filed under asteroid, astrochemistry, astrogeology, Bennu, biochemistry, Carbonaceous Asteroid, Nature via PubMed, organic chemistry, phyllosilicates, planetary protection, prebiotic chemistry, Sample Return

Nitrogen- And Oxygen-Rich Organic Material Indicative Of Polymerization In Pre-aqueous Cryochemistry On Bennu’s Parent Body — a, STEM high-angle annular dark field (HAADF) + EDS image of Particle 2. A nitrogenous vein (green) is sandwiched between phyllosilicate regions (purple). A circular region shows the location of a selected area electron diffraction acquisition shown in b. The Pt and Si deposition and redeposition layers were created during the FIB processing. b, Selected area electron diffraction shows that the nitrogenous vein is amorphous. c, SEM backscatter plus EDS view of the larger particle before the FIB section was extracted. The substrate is diamond; only N was used for the green channel. The line shows the location of the FIB liftout; the dashed portion of the line is outside the field of view in a. d, EDS spectrum of the CNO peaks of the organic phase along with the fit used for quantification. dep, deposition; redep, redeposition.

Nitrogen-containing organic compounds play key biological roles, and their identification in primitive astromaterials such as meteorites can shed light on the origin of life.

However, meteorites are typically contaminated by uncontrolled exposure to Earth. Here we show that pristine samples returned from asteroid Bennu contain polymeric organics exceptionally rich in nitrogen and oxygen.

These polymers contain a variety of functional groups including amines, amides, N-heterocycles, and aliphatic and aromatic hydrocarbons, among others. They are seen in a carbonaceous vein with mineral inclusions and in multilayered organic sheets. Their morphology and composition indicate formation from pre-aqueous N-rich precursors and later modification during aqueous alteration.

These findings demonstrate that asteroids like Bennu contain complex nitrogen-rich organic phases formed by pre-aqueous and aqueous processes, and they expand the known inventory of potential prebiotic extraterrestrial compounds.

A, Image of Particle 33 immediately after lifting from diamond substrate. The upper right corner that was measured using SEM/EDS shattered. B, SEM image of the region analyzed by EDS. Some phyllosilicates sitting on the surface mobilized during scanning. C, C-K (red), N-K (green), and O-K (blue) map showing nitrogen is abundant in Particle 33 but not in the phyllosilicates or diamond substrate. D, Fe-L (red), Mg-K (green), O-K (blue) map showing the location of the phyllosilicates (light blue/white), and that Particle 33 contains O but the diamond substrate does not.

Nitrogen- and oxygen-rich organic material indicative of polymerization in pre-aqueous cryochemistry on Bennu’s parent body, Nature via PubMed

Astrobiology, Astrochemistry,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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