Scientists identify all DNA and RNA bases in meteorites

Scientists have identified all five canonical nucleobases used in DNA and RNA in extraterrestrial material, according to peer-reviewed research published in 2022 and 2026. The molecules are adenine, guanine, cytosine, thymine and uracil — the chemical bases that store genetic information in terrestrial biology. The new attention on the finding followed a May 21 social-media post that pointed to meteorites as evidence that some ingredients for life existed in space before life emerged on Earth. The papers do not say life came from space, but they do report that these compounds occur in carbon-rich meteorites and in samples returned from asteroid Ryugu. ### Which molecules did scientists actually find? Nature Communications reported in 2022 that researchers identified “all DNA/RNA nucleobases” in carbonaceous meteorites. That paper described a broad set of extraterrestrial purine and pyrimidine compounds and said the meteorites contained the canonical bases needed for DNA and RNA chemistry. Nature Astronomy reported in 2026 that Ryugu, a carbon-rich asteroid sampled by Japan’s Hayabusa2 mission, also contained all five canonical nucleobases. (nature.com) A related Nature Astronomy commentary published on May 21 said Ryugu contains all five nucleobases used in DNA and RNA. ### Why is “all DNA and RNA bases” a specific claim? The five canonical bases are adenine, guanine, cytosine, thymine and uracil. (nature.com) DNA uses adenine, guanine, cytosine and thymine, while RNA uses adenine, guanine, cytosine and uracil. Saying scientists found “all DNA and RNA bases” means the full canonical set has now been reported in extraterrestrial samples, rather than only a subset. (nature.com) ### Were these found in meteorites, asteroid samples, or both? Carbonaceous meteorites were the basis of the 2022 Nature Communications paper. That study said a diversity of meteoritic nucleobases could have served as building blocks of DNA and RNA on the early Earth. Ryugu samples were the basis of the 2026 Nature Astronomy paper. Because Ryugu material was collected directly in space and returned to Earth by Hayabusa2, the sample set gives researchers a way to study primitive asteroid chemistry with less concern about terrestrial contamination than with meteorites recovered on Earth. (news.sciandnature.com) That contamination point is an inference from the returned-sample design and the long-standing challenge of Earth exposure in meteorite work. (nature.com) ### Does this mean scientists found life in space? The papers report organic molecules, not living organisms. Nucleobases are chemical building blocks of nucleic acids, but by themselves they are not evidence of biology. The 2022 paper said the discovery adds to evidence that prebiotic compounds relevant to life’s chemistry were present in extraterrestrial material. Science has previously described the broader question as whether life’s ingredients formed in space, on Earth, or through both routes. (nature.com) The new work fits into that prebiotic-chemistry debate by expanding the list of biologically relevant compounds detected beyond Earth. ### Why are researchers focused on carbonaceous rocks like Murchison and Ryugu? Carbonaceous meteorites are known for containing water-bearing minerals and organic compounds. (nature.com) Earlier work on the Murchison meteorite reported extraterrestrial nucleobases, and later studies expanded that inventory. Ryugu is of interest for the same reason: it is a primitive, carbon-rich body thought to preserve early Solar System chemistry. (science.org) Nature Astronomy’s 2026 paper also linked differences in nucleobase distribution to ammonia levels in samples, indicating that local chemical conditions inside asteroid parent bodies may affect which compounds form. ### What comes next for this line of research? Hayabusa2’s Ryugu samples remain an active source of analysis, and researchers are continuing to compare returned asteroid material with meteorites recovered on Earth. (arxiv.org) Future work is likely to focus on how these nucleobases formed, how abundant they were, and whether other prebiotic ingredients such as sugars and phosphates can be tied to the same extraterrestrial environments. Those next steps follow directly from the questions raised in the Nature Communications and Nature Astronomy papers. (nature.com 1) (nature.com 2)