TOKYO, Aug 16, 2022 (BSS/AFP) - Water may have been brought to Earth by

asteroids from the outer edges of the solar system, scientists said after
analysing rare samples collected on a six-year Japanese space mission.

In a quest to shed light on the origins of life and the formation of the
universe, researchers are scrutinising material brought back to earth in 2020
from the asteroid Ryugu.

The 5.4 grams (0.2 ounces) of rocks and dust were gathered by a Japanese
space probe, called Hayabusa-2, that landed on the celestial body and fired
an "impactor" into its surface.

Studies on the material are beginning to be published, and in June, one group
of researchers said they had found organic material which showed that some of
the building blocks of life on Earth, amino acids, may have been formed in
space.

In a new paper published in the journal Nature Astronomy, scientists said the
Ryugu samples could give clues to the mystery of how oceans appeared on Earth
billions of years ago.

"Volatile and organic-rich C-type asteroids may have been one of the main
sources of Earth's water," said the study by scientists from Japan and other
countries, published Monday.

"The delivery of volatiles (that is, organics and water) to the Earth is
still a subject of notable debate," it said.

But the organic materials found "in Ryugu particles, identified in this
study, probably represent one important source of volatiles".

The scientists hypothesised that such material probably has an "outer Solar
System origin", but said it was "unlikely to be the only source of volatiles
delivered to the early Earth".

Hayabusa-2 was launched in 2014 on its mission to Ryugu, around 300 million
kilometres away, and returned to Earth's orbit two years ago to drop off a
capsule containing the sample.

In the Nature Astronomy study, the researchers again hailed the findings made
possible by the mission.

"Ryugu particles are undoubtedly among the most uncontaminated Solar System
materials available for laboratory study and ongoing investigations of these
precious samples will certainly expand our understanding of early Solar
System processes," the study said.