The latest research has simultaneously discovered for the first time all five "letters" of the genetic code of life - adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) - in samples from the asteroid Ryugu. These molecules are the basic nitrogen-containing organic compounds that encode genetic information in DNA and RNA and are considered the core building blocks of life.
The samples were collected from the surface and underground of Ryugu by Japan's JAXA's Hayabusa2 probe and brought back to Earth in 2020. They were extracted and purified with water and hydrochloric acid in an ultra-clean laboratory for analysis. The scientific research team detected the above five nucleobases in both samples, and the contents of purines (A, G) and pyrimidines (C, T, U) were roughly equal. This is in sharp contrast to the skewed distribution previously observed in the Murchison meteorite, Olga meteorite and asteroid Bennu samples.
Researchers pointed out that this discovery does not mean that there is life on Ryugu, but it strongly implies that the chemical raw materials required for life may be quite common in the early solar system, and may have been transported to the early Earth through C-type asteroids rich in organic matter and water. Combined with the previous confirmation of all five nucleobases in the Bennu sample, the scientific community is increasingly inclined to believe that the key molecules of life may be natural products of the chemical evolution of the universe, rather than accidental events unique to the Earth.
