How did life develop on Terre ? Samples made by a Japanese space probe in 2019 might help us learn more regarding the origin of our planet. They have in fact made it possible to discover amino acids in samples of matter from of an asteroidaccording to a Japanese scientific study published on Friday.
These amino acids and other organic materials were taken from the asteroid Ryugu, say researchers from Okayama University (western Japan). “The discovery of amino acids capable of forming proteins is significant, because Ryugu was not exposed to the Earth’s biosphere, unlike meteorites”, can we read in this study. Therefore, “their detection proves that at least some of these elementary bricks of life on Earth might have been formed in space environments”, add the scientists.
An asteroid located more than 300 million kilometers from Earth
The researchers said they identified 23 different types of amino acids in 5.4 grams of black rock and dust samples collected on Ryugu by Japan’s Hayabusa-2 probe. This capsule had returned to Earth at the end of 2020 with its precious cargo following a six-year mission.
Discovered in 1999, the asteroid Ryugu (“Dragon Palace” in Japanese) is located more than 300 million kilometers from our planet and is less than 900 meters in diameter. Scientists believe that some of the asteroid’s material was created around five million years following the birth of our solar system and was not heated above 100 degrees Celsius.
Amino acids brought to Earth from space?
According to another study published Thursday in the American journal Sciencematerial taken from Ryugu has “a chemical composition that more closely resembles that of the Sun’s photosphere” than that of meteorites.
The Ryugu samples “give reason to believe that the amino acids were brought to Earth from space”, confirms Kensei Kobayashi, an astrobiologist and professor emeritus at Yokohama National University interviewed by AFP. Another theory is that amino acids were created in Earth’s early atmosphere via lightning.
