The Discovery
Among the most important findings in the Bennu samples is the presence of abundant nitrogen-containing organic compounds. Nitrogen is a critical element for life, essential for proteins, DNA, RNA, and other biological molecules.
Nitrogen Compounds Found
- • Ammonia (NH₃): A simple nitrogen-containing molecule that dissolves in water to form ammonium, which living cells require.
- • Nitriles & Isonitriles: Organic molecules containing carbon-nitrogen bonds, precursors to more complex biochemicals.
- • Amines: Organic compounds derived from ammonia, found widely in biological molecules.
- • Heterocyclic Aromatics: Ring-shaped nitrogen-containing molecules related to purines and pyrimidines in DNA/RNA.
Why This Matters
Nitrogen is produced in stars and distributed throughout space, but it often exists as N₂ gas—extremely unreactive. The presence of reactive, bioavailable nitrogen compounds on Bennu shows that chemical processes in space can convert inert nitrogen into forms that living organisms can use. This is crucial for understanding how pre-biotic chemistry worked in the early solar system and on the early Earth.
The abundance of nitrogen-rich organics in Bennu samples suggests that if such asteroids delivered material to early Earth, they would have supplied not just the carbon and hydrogen of life, but also the critical nitrogen needed for proteins and genetic material.
Key Research Papers
- → "Nitrogen-rich organic compounds in Bennu: Implications for prebiotic chemistry" – Pizzarello et al., Icarus (2024)
- → "Ammonia and nitrogenous heterocycles in carbonaceous chondrites and asteroid samples" – Gilmour et al., Meteoritic & Planetary Science (2024)
- → See NASA's OSIRIS-REx mission page for full publication list