These “bricks of life” were brought back by the space probe Hayabusa2, and very carefully studied in a clean room last year. The Japanese scientific team detected 20 different amino acids, which could strengthen the hypothesis of the appearance of life on Earth after an asteroid bombardment.
Let’s not forget that more samples are on the way back!
An adventure for a few grams
On December 5, 2020, the Hayabusa2 mission reached the end of its main objective: to bring samples collected twice to the surface of the asteroid Ryugu. A journey that lasted six years, and studied in detail the surface of this small asteroid 950 meters in diameter. Which is not a rock, but an agglomerate of blocks that gravity has assembled in a slow ballet over hundreds of millions, even billions of years.
With 5.4 grams collected, one may have the impression that there will not be enough to study, but in reality the probe has brought back a real treasure: even microscopic grains of matter are enough. Part of it had been harvested from a crater formed by a high-speed impactor sent by Hayabusa2.
Bringing Acids Home
” Samples taken from Ryugu represent the most primitive material we have ever studied in the Solar System “, explains Hisayoshi Yurimoto, geologist at the University of Hokkaido and responsible for the chemical analysis.
Unlike terrestrial organic molecules, elements taken from Ryugu (a C- or Carbon-type asteroid) were not altered by a humid, saline environment or atmosphere, making their composition closer to that of the Solar System as he was in his early years. The researchers detected many organic compounds, including proteinogenic amino acids (which are the “building blocks of life”), but also polycyclic aromatic hydrocarbons, which play a major role in interstellar dust. 20 different amino acids have been identified.
Other studies in sight
” Proving the presence of amino acids on the surface, and under the surface of an asteroid increases the probability that these compounds have arrived on Earth from space “, details Kensei Kobayashi, even if that does not make it a formal proof.
However, this is good news for exobiology, because if the bombardment of the Earth billions of years ago brought amino acids there, then these probably ended up on other planets, and the process may have existed in our solar system as elsewhere.
Following this discovery, the scientific teams are all the more eager to recover other samples which are on the way. Indeed, another carbonaceous asteroid (Bennu) has been sampled via the NASA OSIRIS-REx mission which is on its way back to deposit its harvest on September 23, 2023. A great opportunity to know more…
On the same subject :
A treasure: diving into the figures of the 3rd catalog of the Gaia telescope
Source : sciencealert
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