A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu

Abstract Organic molecules delivered from extraterrestrial materials may have played a key role in supplying building blocks for life on Earth. Here we report all five canonical nucleobases—purines (adenine and guanine) and pyrimidines (cytosine, thymine and uracil)—in samples returned from the C-type asteroid (162173) Ryugu by JAXA’s Hayabusa2 mission and compare the results with data from similar extraterrestrial material. Ryugu samples contain nearly equal amounts of purines and pyrimidines, whereas Murchison is enriched in purines and Bennu and Orgueil in pyrimidines. Samples from Ryugu, Bennu and Orgueil, which have a similar mineralogy and elemental composition, show purine-to-pyrimidine ratios…

• KU
  Keio University
• HU
  Hokkaido University
• JS
  Japan Society for the Promotion of Science

  Awards: 21J00504, 21H04501, 25H00677, 25K17463, 23H00148, 21H05414, 21KK0062
• JA
  Japan Agency for Marine-Earth Science and Technology
• JA
  Japan Aerospace Exploration Agency
• IO
  Institute of Space and Astronautical Science