Overview
- Researchers identified adenine, guanine, cytosine, thymine, and uracil in two independent Ryugu subsamples, with structural isomers bolstering an indigenous, non-terrestrial origin.
- The result corroborates 2025 findings from NASA’s Bennu sample return, alongside earlier meteorite detections, indicating these molecules are widespread in carbonaceous materials.
- Ryugu shows roughly equal purine and pyrimidine abundances, contrasting with pyrimidine-rich Bennu and Orgueil and purine-rich Murchison, highlighting parent-body chemical variation.
- A newly reported correlation links lower purine-to-pyrimidine ratios with higher ammonia, a relationship not predicted by existing models that is prompting targeted laboratory tests and broader sample surveys.
- Authors stress the detections do not indicate life on the asteroid, noting the Hayabusa2 cache totals about 5.4 grams and that milligram-scale portions were examined using high-resolution mass spectrometry under strict contamination control.