It may have been the Sun that sent water to Earth

Scientists from Australia's Curtin University have shown how the Sun may have played an unexpected role in the formation of the "Blue Planet".

The study, published in the Nature Astronomy journal on Monday, made the case that hydrogen ions emitted by the Sun were carried by solar winds onto asteroids that eventually crashed into Earth and were later converted into water.

Contributing author and director of Curtin University's Space Science and Technology Centre (SSTC) Professor Phil Bland said analysis of existing theories "didn't match with the water found on Earth", which prompted the international team of researchers to search for an explanation of the unaccounted water.

"Our research suggests the solar wind created water on the surface of tiny dust grains and this isotopically lighter water likely provided the remainder of the Earth's water," Bland said.

Previously the most widely accepted theory for the origin of Earth's water, posited that water came from bodies of icy cosmic dust, or planetesimals, from outside of our solar system, Xinhua news agency reported.

The results came from a detailed analysis of dense, near earth "S-type" asteroids, using samples collected by Japanese space probe Hayabusa over a decade ago.

"We found [the samples] contained enough water that, if scaled up, would amount to about 20 litres for every cubic metre of rock," Bland said.

The discovery bears major implications in the understanding of life on Earth, as the prevalence of water, covering over 70 per cent of the Earth's surface, and has been key to the evolution of the planet and the life that has inhabited it.

Lead author Dr. Luke Daly of the University of Glasgow said the research could also unlock new potential in crewed space travel, for which water supply is a major limiting factor.

"How astronauts would get sufficient water, without carrying supplies, is one of the barriers of future space exploration," said Daly. "Astronauts may be able to process fresh supplies of water straight from the dust on a planet's surface, such as the Moon."