Overview
- A PNAS paper led by Angel Mojarro details a confident but not yet conclusive detection of tryptophan in about 50 milligrams of Bennu material.
- Confirmation would lift Bennu’s tally to 15 of the 20 protein-building amino acids, complementing prior finds of all five common nucleobases.
- Scientists say the sample’s sealed return lowers the risk of terrestrial contamination, though enantiomeric and isotopic analyses are required to confirm provenance.
- Tryptophan’s fragility likely explains its absence in meteorites that endure atmospheric heating, highlighting the unique value of pristine sample returns.
- The study also indicates heterogeneous, water-influenced chemistry across Bennu’s rocks, pointing to multiple environments that produced its diverse organics.