The ingredients of life have for the first time been found on an asteroid that might one day crash into Earth.
A single grain of the asteroid Itokawa, visited by a Japanese space probe a decade ago, contains both water and organic matter, new research has found.
The finding suggests other asteroids contain the "raw ingredients of life", researchers at Royal Holloway, University of London said in a statement.
"After being studied in great detail by an international team of researchers, our analysis of a single grain, nicknamed 'Amazon', has preserved both primitive (unheated) and processed (heated) organic matter within ten microns (a thousandth of a centimeter) of distance," said astrobiologist Queenie Chan.
"The organic matter that has been heated indicates that the asteroid had been heated to over 600C in the past. The presence of unheated organic matter very close to it, means that the in-fall of primitive organics arrived on the surface of Itokawa after the asteroid had cooled down."
Meaning the asteroid was picking up new organic compounds in its travels through space.
"These findings are really exciting as they reveal complex details of an asteroid's history and how its evolution pathway is so similar to that of the prebiotic Earth."
Later missions to asteroids like Bennu and Ryugu have found evidence of "exogenous materials", she said, but it's not yet known what they are.
"Our findings suggest that mixing of materials is a common process in our solar system," she said.
Itokawa is classified as a potentially hazardous asteroid, meaning there's a small chance it could one day hit the Earth. Its orbit takes it past Earth about once every two years.
