In 2018, the OSIRIS-REx mission collected samples from Bennu. The first study, by international authors, analysed the samples to reveal thousands of organic molecular compounds, including 14 of the 20 amino acids present in life on Earth, 19 non-protein amino acids rare or absent in known biology, and all five DNA and RNA bases.

Bennu was also found to be rich in nitrogen and ammonia, which formed billions of years ago in cold, distant regions of our Solar System. In the second study, international and Australian scientists found salts, which the team says may have formed during the evaporation of brine on Bennu’s parent body, indicating that water was present there.

The potential presence of water, together with nucleobases, raises questions about the process that creates the building blocks for life, they say. In conclusion, the authors say Bennu has a much richer complexity in organic matter than here on Earth, and suggest that its parent body may have come from the outer Solar System.