Overview
- Peer-reviewed analyses in Nature Astronomy report all five canonical nucleobases in contamination-controlled, milligram-scale samples from asteroid Ryugu.
- Higher-sensitivity methods and larger subsamples resolved earlier non-detections in Ryugu, confirming adenine, guanine, cytosine, thymine, and uracil.
- Ryugu shows a roughly balanced purine-to-pyrimidine profile that differs from Bennu and many meteorites, indicating diverse parent-body chemistries.
- The study identifies a correlation between lower purine-to-pyrimidine ratios and higher ammonia, a clue researchers are using to probe formation mechanisms.
- Hayabusa2 collected the material in 2018–19 and returned it in December 2020, reducing contamination risks; scientists stress the detections do not indicate life but support asteroid delivery of prebiotic organics to early Earth.