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Tokyo (AFP) – Grains of dust recovered by a Japanese spacecraft from an asteroid some 300 million kilometers from Earth have revealed a surprising component: a droplet of water, scientists said on Friday.
The discovery provides new support for the theory that life on Earth was seeded from space.
The findings are included in the latest research, which comes from analyzing 5.4 grams of rock and dust collected by the Hayabusa-2 probe from the asteroid Ryugu.
“This drop of water has great significance,” lead scientist Tomoki Nakamura of Tohoku University told reporters before the research was published in Science magazine on Friday.
“Many researchers believe water was brought in (from space), but we actually discovered water for the first time in Ryugu, an asteroid near Earth.”
Hayabusa-2 was launched on its mission to Ryugu in 2014 and returned to Earth orbit two years ago to drop a capsule containing the sample.
The precious cargo has already yielded several insights, including organic material showing that some of the building blocks of life on Earth, amino acids, may have been formed in space.
The study, released Friday, says the team found a drop of liquid in the Ryugu sample “which was carbonated water that contained salt and organic matter,” Nakamura said.
This supports the theory that asteroids like Ryugu or its larger parent asteroid may have “provided water containing salt and organic material” in collisions with Earth, Nakamura said.
“We have discovered evidence that this (process) may be directly related to, for example, the origin of the oceans or organic matter on Earth.”
Nakamura’s team of about 150 researchers — including 30 from the United States, Britain, France, Italy, and China — is one of the largest teams analyzing Ryugu’s sample.
The sample was split between different scientific teams to maximize the chance of new discoveries.
Kensei Kobayashi, an astrobiology expert and professor emeritus at Yokohama National University who is not part of the research group, welcomed the discovery.
“The fact that water was discovered in the sample itself is surprising,” he told AFP given its fragility and the likelihood of it being destroyed in space.
“It suggests that the asteroid contained water – in the form of liquid and not just ice – and that organic material may have been produced in that water.”
© 2022 AFP