Organic #molecules delivered from #extraterrestrial materials may have played a key role in supplying building blocks for #life on #Earth.
Now scientists 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.
Samples from Ryugu, #Bennu and #Orgueil, which have a similar mineralogy and elemental composition, show purine-to-pyrimidine ratios negatively correlating with #ammonia.
These observations indicate that the nucleobases in these samples may have formed via a shared pathway depending on the physicochemical environment of the respective parent bodies.
The detection of diverse nucleobases in asteroid and meteorite materials demonstrates their widespread presence throughout the Solar System and reinforces the hypothesis that carbonaceous asteroids contributed to the #prebiotic chemical inventory of early Earth.
#astronomy #astrobiology
https://www.nature.com/articles/s41550-026-02791-z

A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu - Nature Astronomy
Samples returned from the asteroid Ryugu contain all five canonical nucleobases (A, G, C, T and U). Their presence in Ryugu and Bennu supports the hypothesis that carbonaceous asteroids contributed to the prebiotic chemical inventory of early Earth.



