A close-up of the surface of the asteroid Ryugu
All five key ingredients of DNA and RNA were found in samples from the asteroid Ryugu. This reinforces the idea that asteroids may have brought the ingredients for the first living organisms to Earth long ago.
The Japanese Hayabusa 2 spacecraft visited Ryugu in 2018, where it fired two projectiles – one small and one large – at the asteroid’s surface and collected the resulting debris. He returned to Earth with the samples in 2020 and researchers have been analyzing them in detail ever since.
Researchers at Hokkaido University in Japan examined two samples, one from the asteroid’s surface and the other composed of subsurface materials excavated by the projectiles. The results were published on Monday, in an article in Nature.
In both, the team found all five main nucleobaseswhich are the compounds that form the nucleic acids DNA and RNA when combined with sugars and phosphoric acid.
As , this is not the first time that nucleobases have been found in asteroid samples: they have also been observed in meteorites and in samples from the asteroid .
The fact that nucleobases have been found in samples from asteroids like Bennu and now Ryugu points to the potential importance of asteroids in the history of life on Earth.
“Its detection in Ryugu strongly supports its ubiquity in the solar system”, he told New Scientist, Yasuhiro Obawhich was part of the study.
If asteroids across the solar system are full of the building blocks of DNA, they may have brought them to Earth billions of years ago and helped kickstart the development of life.
It’s even possible that Ryugu and other asteroids have DNA and RNA in them, not just their components. “It is very likely that more complex organic molecules such as nucleic acids will form on asteroids”, highlights Oba. This could make asteroids even more important for the beginnings of life on Earth.
