Half of the Earth's water could come from old asteroid collisions

The idea of an asteroid hitting the Earth often positions itself as a catastrophic event that decimates all life on Earth. However, many scientists believe that asteroids can also help life flourish, providing water to the planet billions of years ago.

A new study on samples of the peanut-shaped Asteroid Itokawa, published in the journal Science Advances on May 1, suggests that it contained water, suggesting that similar objects of the The old solar system would have been the same and could have sown the primitive Earth. with vital water.

In 2000, JAXA, the Japanese aerospace exploration agency, sent the Hayabusa probe to the asteroid Itokawa to try to take samples from the rock and bring them back to Earth. After a first unsuccessful attempt, the probe was able to pick up dust and return to Earth, landing in a remote area of ​​the Australian outback in June 2010. It was the first time that samples of asteroids were brought back to Earth. Scientists study the samples returned since, even showing us exactly what Itokawa looks like under a microscope.

The research team at the University of Arizona received five extremely tiny samples from the JAXA, about one-fifth the width of a hair, and decided to look for water, which no other team was doing with the Itokawa samples.

"Until we proposed it, nobody thought of looking for water," said Maitrayee Bose, co-author of the newspaper, in a statement. "I am pleased to announce that our intuition has paid off."

Bose and lead author, Ziliang Jin, studied the isotopes of hydrogen and the water content of Itokawa, revealing that the S – type asteroid (non – metallic) exhibited levels of isotopes similar to those that we would find in the rocks of the Earth. Although it is about 8 million years old (and its dust and soil are probably much older), the team has found evidence that the specimens are so thin. Itokawa were rich in water.

The team hypothesized that their discoveries reveal an extraterrestrial origin for almost half of the Earth's water, but it is to be expected, however, that there is still work to be done – is that the first example of asteroid sample return mission result.

"Sample return missions are mandatory if we really want to study planetary objects in depth," notes Bose.

The good news is that two similar asteroid missions are in progress, with Hayabusa's successor, Hayabusa-2, making a hole in the Ryugu asteroid to extract samples and bring them back to Earth in 2020. NASA has also launched a study by an asteroid of the potentially dangerous object called Bennu, who launched the OSIRIS-REx in 2016 high-five the asteroid and steal a handful of old dust. This spaceship is expected to return in 2023.

As such, new evidence of the origins of the most valuable resource on our planet may be at hand.