How water on asteroid could help to explain life on Earth

WATER and organic matter found on the surface of an asteroid could explain how life formed on Earth, the first sample of its kind has revealed.

Researchers at Royal Holloway, University of London, analysed a “grain” from the “Itokawa” asteroid and found its chemistry had evolved over time.

Their findings, published today in the journal Scientific Reports, reveal “complex details” of the asteroid’s history and could help explain Earth’s evolution, they said.

Samples from Itokawa were brought back from the inner Solar System by the Japan Aerospace Exploration Agency’s first Hayabusa mission in 2010.

A team of international researchers analysed the single grain sample, nicknamed “Amazon”, and discovered both unheated and heated organic matter.

“The organic matter that has been heated indicates that the asteroid had been heated to over 600C [1,112F] in the past,” said Dr Queenie Chan, an Earth scientist at Royal Holloway.

“The presence of unheated organic matter very close to it, means that the infall of primitive organics arrived on the surface of Itokawa after the asteroid had cooled down.”

Itokawa has evolved over billions of years, the findings suggest, by taking in water and organic materials from foreign space matter – similar to Earth.

The asteroid would have undergone extreme heating, dehydration and “shattering” in an impact around 1.31.4billion years ago, the team said. It reformed from the shattered fragments and “rehydrated itself ” with water from carbon-rich meteorites or infall of dust.

Itokawa is an S-type asteroid, similar to most of Earth’s meteorites, and these latest findings reveal they contain “raw ingredients of life”, the researchers said.