All five DNA and RNA nucleobases found in asteroid Ryugu samples

Overview

Updated 1 hour ago

Japan's Hayabusa2 spacecraft dropped 5.4 grams of asteroid Ryugu onto Earth in 2020. In March 2026, researchers reported that those pristine grains contain all five nucleobases used in DNA and RNA.

The finding means the molecular letters of genetic code can form and survive on carbon-rich asteroids. It does not mean life existed on Ryugu. It means the raw chemistry for life was present in the early solar system.

Why it matters

If the building blocks of DNA can form on multiple asteroids, the raw chemistry for life may be common across the solar system.

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Key Indicators

Nucleobases detected in Ryugu samples

Adenine, guanine, cytosine, thymine and uracil were all found.

5.4 g

Ryugu material returned by Hayabusa2

The mission delivered pristine asteroid grains in 2020.

4.5 billion years

Age of asteroid material

Ryugu is a remnant from the early solar system.

Asteroids with all five nucleobases confirmed

Ryugu and Bennu have both yielded the complete set.

Ryugu samples analyzed

Researchers tested two separate samples from the mission.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Toshiki Koga

Biogeochemist at JAMSTEC and lead author of the Ryugu nucleobase study

Lead author of the Nature Astronomy paper

César Menor Salván

Astrobiologist at the University of Alcalá in Spain

Independent researcher not involved in the Ryugu study

Organizations Involved

Japan Agency for Marine-Earth Science and Technology (JAMSTEC)

Research institute

Led the team that confirmed all five nucleobases in Ryugu samples

JAMSTEC is a Japanese research institute that studies the ocean, Earth and life sciences.

Japan Aerospace Exploration Agency (JAXA)

Space agency

Operated Hayabusa2, which returned Ryugu samples in 2020

JAXA is Japan's national space agency and the operator of the Hayabusa2 asteroid mission.

NASA OSIRIS-REx mission

NASA sample-return mission

Returned Bennu samples in 2023; all five nucleobases reported in 2025

OSIRIS-REx is NASA's mission to asteroid Bennu and the source of a second pristine asteroid sample set.

Timeline

2020 November 2026

6 events Latest: Today

Tap a bar to jump to that date

November 2026
ScienceDaily publishes report on Ryugu nucleobases
Today Publication

The outlet describes the discovery and its implications for early solar system chemistry.
Today
March 2026
JAMSTEC announces the findings
Statement

The institute reports a complete set of nucleobases in Ryugu.
March 17th, 2026
Nature Astronomy publishes Ryugu study
Publication

Researchers confirm all five canonical nucleobases in two Ryugu samples.
March 16th, 2026
2025
Bennu samples yield all five nucleobases
Research

NASA's asteroid sample confirmed the complete set in pristine material.
2025
2023
Uracil detected in Ryugu samples
Research

An international team reported one nucleobase in the asteroid material.
2023
2020
Hayabusa2 returns Ryugu material
Mission

The spacecraft delivered 5.4 grams of pristine asteroid grains to Earth.
2020

Scenarios

Additional asteroid samples confirm all five nucleobases

Likely Resolves by End of 2028

Discussed by: JAMSTEC and NASA researchers, cited in the Nature Astronomy study and Ars Technica

The Ryugu result matches Bennu. If more sample-return missions find the same set, the chemistry looks common rather than rare.

Lab experiment reproduces Ryugu's ammonia-linked nucleobase ratio

Possible Resolves by Q2 2028

Discussed by: Study authors in Nature Astronomy

The team found a correlation between ammonia abundance and the purine-to-pyrimidine ratio. A lab synthesis that reproduces it would show how the molecules formed.

Independent team challenges Ryugu nucleobase detection

Unlikely Resolves by End of 2027

Discussed by: Ars Technica, which notes past meteorite nucleobase findings faced contamination questions

Pristine sample return was designed to rule out Earth contamination. A credible challenge would need to show the molecules came from handling or the spacecraft.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

1969

Murchison meteorite (1969)

The Murchison meteorite fell in Australia in 1969. It contained amino acids and nucleobases, but its passage through Earth's atmosphere and landing left open the possibility of contamination.

Then

Researchers used it to argue that organic chemistry is common in space.

Now

Murchison became a benchmark for meteorite organics, but contamination questions limited how far the nucleobase findings could be pushed.

Why this matters now

Ryugu's pristine samples were collected in space, avoiding the contamination problem that dogged Murchison.

2023-2025