Samples from asteroid Ryugu contain all five canonical nucleobases, the key components of DNA and RNA. Japan's Hayabusa2 spacecraft collected the material during its 2018 visit and returned it to Earth in 2020. The discovery supports the idea that asteroids delivered life's building blocks to Earth billions of years ago.
In 2018, Japan's Hayabusa2 spacecraft approached the near-Earth asteroid Ryugu. It fired two projectiles—one small and one large—into the surface to collect debris, including subsurface material. The probe returned these samples to Earth in 2020, where researchers have since conducted detailed analyses. Yasuhiro Oba at Hokkaido University in Japan and colleagues studied two samples: one from the surface and one from subsurface layers. Both contained all five primary nucleobases, the compounds that form the basis of nucleic acids DNA and RNA when linked with sugars and phosphoric acid. Nucleobases have previously appeared in meteorites and samples from asteroid Bennu, though with varying abundances across sources. These differences may help trace fragments back to their parent asteroids and track the evolution of those bodies. The findings indicate nucleobases are widespread in the solar system. “Their detection in Ryugu strongly supports their ubiquity in the solar system,” Oba said. He added, “It is very likely that more complex organic molecules like nucleic acids are formed on asteroids.” The research appears in Nature Astronomy (DOI: 10.1038/s41550-026-02791-z).