All five “letters” of DNA and RNA found in samples from asteroid Ryugu

Nov 6 · Nature Astronomy

A Japanese team led by Toshiki Koga and Yasuhiro Oba reports in Nature Astronomy that two grains of asteroid Ryugu, brought to Earth by JAXA’s Hayabusa2, contain all five canonical nucleobases: adenine, guanine, cytosine, thymine and uracil, in roughly similar amounts in both. A 2023 study had found only uracil. Because the samples were collected in space, sealed and handled in ultra-clean labs, contamination on Earth is very unlikely — the problem that always shadowed similar finds in meteorites. NASA’s Bennu samples gave the same full set in 2025. Caveat: these molecules form without life; the finding says the raw parts were common in the early Solar System, not that life was there.

Source: Nature Astronomy ↗