The theory of water arriving on Earth via asteroids is reinforced by a Japanese study

Where does the water come fromcovers more than 70% of the surface of our planet? Analysis of the composition of samples from the asteroid Ryugu accredits the theory of an extraterrestrial origin of water, according to a Japanese study published (link in English) in the scientific journal Nature Astronomy, Monday August 15.

C-type asteroids, such as Ryugu, “rich in volatile substances”i.e. able to pass easily from the solid state to the gaseous state, “and organic”, “could have been one of the main sources of water on Earth”according to this study. “The contribution to the Earth of volatile substances, i.e. organic matter and water, is still the subject of an important debate”say the authors.

“Ongoing research on these valuable samples will certainly expand our understanding of early solar system processes.”

the authors of the study

in the journal “Nature Astronomy”

Discovered in 1999, the asteroid Ryugu is located more than 300 million kilometers from our planet and is less than 900 meters in diameter. Scientists believe that some of the material from this asteroid was created around five million years after the birth of our solar system and was not heated above 100°C.

In 2019, the Japanese probe Hayabusa-2 managed to collect 5.4 grams of rock and black dust from Ryugu. A capsule containing this exceptional cargo had returned to Earth at the end of 2020. In June, another Japanese scientific study had thus revealed the presence in these samples of amino acids, molecules at the base of life, because capable of forming proteins in combining with each other.