Scientists Find All Five DNA and RNA Bases in Asteroid Ryugu

Pristine material collected from asteroid Ryugu contains all five nucleobases used to encode genetic information in DNA and RNA, according to Japanese researchers. The findings, published in Nature Astronomy and reported on November 3, 2026, provide further evidence that essential chemical ingredients for life existed throughout the early Solar System. The discovery establishes the presence of adenine, guanine, cytosine, thymine and uracil in samples returned by Japan Aerospace Exploration Agency's (JAXA) Hayabusa2 mission.

These nitrogen-containing molecules form the fundamental components of genetic information in living organisms. The latest research expands on a 2023 study that identified uracil in Ryugu material. Researchers have now confirmed the presence of the complete set of five canonical nucleobases in two asteroid samples.

According to the study, the five compounds appeared in roughly similar amounts in the analyzed material. Their presence suggests that the chemical ingredients necessary for genetic systems may have been distributed widely across the early Solar System.

Nucleobases are divided into two groups: purines, consisting of adenine and guanine, and pyrimidines, comprising cytosine, thymine and uracil. When combined with sugars and phosphate groups, they form nucleotides, the building blocks of DNA and RNA. Researchers examined material delivered to Earth in 2020 by Hayabusa2. The mission returned approximately 5.4 grams of asteroid particles, which scientists have preserved under carefully controlled laboratory conditions to minimize contamination.

For their analysis, the Japanese team extracted organic compounds using water and hydrochloric acid before purifying the material for molecular identification. The controlled procedure helped researchers investigate the asteroid's original chemical composition without introducing unwanted substances. The results also add to previous discoveries involving meteorites and other asteroid samples. The Murchison meteorite, which fell in Australia in 1969, and the Orgueil meteorite, discovered in France in 1864, have both yielded various organic compounds, including nucleobases.

In 2025, researchers also reported finding all five nucleobases in pristine samples collected from asteroid Bennu by a NASA mission. Unlike meteorites recovered after falling to Earth, these space-returned materials offer researchers better protection against terrestrial contamination. Comparisons between different space rocks reveal variations in their chemical compositions.

Murchison contains relatively higher concentrations of purines, while Bennu and Orgueil show greater amounts of pyrimidines. Scientists believe ammonia may influence these differences because the molecule can affect the chemical reactions involved in nucleobase formation. The contrasting compositions provide clues about the environments and chemical histories of individual asteroids.

The research, led by Toshiki Koga, Yasuhiro Oba, Yoshinori Takano, Hiroshi Naraoka and colleagues, was published in Nature Astronomy under the title A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu. The study appears in volume 10, issue 5, page 655, with DOI 10.1038/s41550-026-02791-z.