Dust specks picked up by a Japanese space probe from an asteroid some 186 million miles (300m kilometers) from Earth have revealed a surprising component: a drop of water.
The discovery lends new support to the theory that life on Earth may have originated in space.
The latest study to be published from the analysis contains findings 5.4 grams of rock and dust collected by the Hayabusa-2 probe From asteroid Ryugu.
“This drop of water has a great meaning,” Tohoku University lead scientist Tomoki Nakamura told reporters before publishing the study in the journal Science on Friday.
“Many researchers believe that water was introduced [from outer space]but we discovered water for the first time on Ryugu, a near-Earth asteroid.”
Hayabusa-2 was launched in 2014 with the Ryuguya mission and returned to Earth orbit two years ago to drop a sample capsule.
The payload has already yielded several insights, including amino acids, an organic material that suggests some of the building blocks of life on Earth may have formed in space.
Nakamura said the team’s latest discovery was a droplet of liquid “containing carbonated water containing salt and organic matter” in the Ryugu sample.
This bolsters the theory that asteroids like Ryugu or its larger parent asteroid could “provide water containing salt and organic matter” upon impact with Earth.
“We found evidence that this could 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, England, France, Italy and China, is one of the largest to analyze the sample from Ryugu.
The sample was split between different scientific groups to increase the chances of new discoveries.
Kensei Kobayashi, an astrobiology expert and professor emeritus of Yokohama National University who was not part of the research team, welcomed the discovery.
“It’s surprising to find water in the sample itself,” he said, given its fragility and the possibility of destruction in space.
“This shows that the asteroid is not just ice, but liquid water, and organic matter has formed in that water.”
