Glasgow scientists may have solved mystery of the origins of Earth’s water

Scientists at the University of Glasgow have been part of an international team which may have solved a key mystery about the origins of the Earth’s water, which may have come from the sun.

In a new paper published today in the journal Nature Astronomy, the researchers from the UK, Australia and America describe how new analysis of an ancient asteroid suggests that extraterrestrial dust grains carried water to Earth as the planet formed.

The water in the grains was produced by space weathering, a process by which charged particles from the Sun known as solar wind altered the chemical composition of the grains to produce water molecules.

Solar system mystery could be solved

The finding could answer the longstanding question of just where the unusually water-rich Earth got the oceans which cover 70 percent of its surface – far more than any other rocky planet in our Solar System.

One theory suggests that one type of water-carrying space rock known as C-type asteroids could have brought water to the planet in the final stages of its formation 4.6 billion years ago.

The early solar system was a very dusty place, providing a great deal of opportunity water to be produced under the surface of spaceborne dust particles.

This water-rich dust, the researchers suggest, would have rained down onto the early Earth alongside C-type asteroids as part of the delivery of Earth’s oceans.

Glasgow leads international research team

The University of Glasgow-led team, headed by Dr Luke Daly, used a cutting-edge analytical process called atom probe tomography to scrutinise samples from a different type of space rock known as an S-type asteroid, which orbit closer to the sun than C-types.

The samples they analysed came from an asteroid called Itokawa, which were collected by the Japanese space probe Hayabusa and returned to Earth in 2010.

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