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TOKYO (AFP) – Asteroid dust collected by a Japanese space probe contains organic material that may have formed in space, some of the building blocks of life on Earth, scientists said Friday.
Ancient material from the asteroid Ryugu was brought back to Earth in 2020 after a six-year mission to the celestial body some 300 million kilometers away.
But scientists are starting to discover its secrets in the first studies on only 5.4 grams (0.2 ounces) of dust and small chunks of dark, tiny rocks.
In a paper published Friday, a group of researchers led by Okayama University in western Japan said they had “discovered amino acids and other organic substances that may provide clues to the origin of life on Earth”.
“The discovery of the amino acids that make up proteins is important, because Ryugu has not been exposed to Earth’s biosphere like meteorites, and thus their identification proves that at least some of the building blocks of life on Earth are in space. atmosphere,” the study said.
The team said they found 23 different types of amino acids when examining a sample collected by Japan’s Hayabusa-2 probe in 2019.
Dust and rocks were stirred up when the frieze-sized spacecraft fired an “impacter” at the asteroid.
“The Ryugu specimen has the most ancient features of any natural specimen available to mankind, including meteorites,” the Japan Aerospace Exploration Agency (JAXA) said in a statement.
Part of the material is thought to have formed about five million years after the birth of the Solar System and has not been heated above 100 °C (210 °F).
Another study published in the US-based journal “Science” states that the material “has a chemical composition that more closely resembles the Sun’s photosphere than other natural samples”.
Kensei Kobayashi, an astrobiology expert and professor emeritus at Yokohama National University, commended the discovery.
“Scientists are questioning how organic matter – including amino acids – was made or where it came from, and the fact that amino acids were discovered in the sample provides a reason to think that amino acids were brought to Earth from outer space,” he told AFP.
Another mainstream theory about the origin of amino acids is that they were created through lightning strikes in Earth’s primitive atmosphere, for example, after the Earth cooled.
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