Mysterious origin of Earth's water may be explained by solar wind

Evidence from asteroids shows that charged particles from the prima tin crook particulate grains into h2o – a process that could beryllium utile for abstraction exploration too

Earth 29 November 2021

By Jonathan O’Callaghan

Illustration of Earth’s bluish aboveground lit up by the sun

Buradaki / Alamy

The sun’s star upwind whitethorn person played a cardinal portion successful delivering h2o to Earth, solving a vexing enigma astir wherever our planet’s seas and oceans came from.

Studies of meteorites person recovered them to beryllium amazingly affluent successful water, suggesting that aboriginal successful our planet’s past 4.6 cardinal years ago, incoming asteroids delivered water and allowed Earth to go the habitable satellite we spot today. However, the creation of the h2o successful meteorites doesn’t precisely lucifer that of Earth’s: the extraterrestrial mentation contains much deuterium, a heavier signifier of hydrogen, indicating that determination indispensable person been different root of the h2o connected our planet.

Luke Daly astatine the University of Glasgow, UK, and his colleagues deliberation they person solved the issue. By studying a azygous atom of worldly returned from asteroid Itokawa by the Japanese spacecraft Hayabusa successful 2010, they recovered grounds that the asteroid had been irradiated by particles successful the star wind, turning a tiny magnitude of each particulate atom into water. “For each metre cubed of [asteroid material], you would get 20 litres of water,” says Daly. Previous probe has shown that asteroids similar Itokawa can incorporate a batch of water, but wherever that h2o would person travel from wasn’t clear.

Our star strategy is thought to person been abundant successful particulate successful its aboriginal phases, truthful immoderate of it could person been turned to h2o by the star wind, earlier streaming down onto Earth’s aboveground aft its formation. Crucially, this h2o contains little deuterium than that delivered by asteroids. “You could nutrient Earth’s oceans by mixing those 2 reservoirs together,” says Daly.

Ashley King astatine the Natural History Museum successful London says that portion scientists person discussed the relation of the star upwind successful Earth’s h2o before, determination has been small grounds that this process takes place. “This is existent grounds that it’s happening,” helium says. “It’s awesome. We tin amusement that mixing that unneurotic with meteorites gives america a truly bully lucifer for Earth’s oceans.”

The method utilized to marque the find progressive studying idiosyncratic atoms from the asteroid utilizing a method known arsenic atom probe tomography, which could beryllium utile successful aboriginal studies. Daly hopes to usage the aforesaid method to survey grains from asteroid Ryugu returned by the Hayabusa 2 ngo successful 2020 to look for akin effects. “It’s going to beryllium truly absorbing to spot if we spot the aforesaid thing,” helium says.

The findings could person implications for abstraction exploration too. “Every rocky aboveground volition person tiny grains that person been irradiated by star wind,” says Daly. “If we privation to enactment up imperishable quality habitation facilities connected different worlds, you could look astatine the [dust] arsenic a mode of producing water.”

Journal reference: Nature Astronomy, DOI: 10.1038/s41550-021-01487-w

More connected these topics:

• water
• space
• sun
• earth