Proof that life came from outer space!

An international team led by researchers from Kyoto University in Japan may have found the origin of nitrogen, which plays a major role in creating the environment that supports life on Earth.

According to new research published in the peer-reviewed scientific journal Nature Astronomy, tiny meteorites that broke off from icy celestial bodies in the outer Solar System carried nitrogen to regions close to Earth in the early days of its formation.

"Our findings raise the possibility that larger amounts of nitrogen compounds than previously recognised were transported close to Earth and served as the building blocks of life on our planet," said Hope Ishii from the research team.

The researchers reached this conclusion by analysing samples from the asteroid Ryugu. An RNA component and vitamin B3 were recently discovered in samples collected from Ryugu by the Japan Space Agency's Hayabusa 2 spacecraft.

The RNA discovery is seen as the strongest evidence yet that the organic building blocks that enable life to begin on Earth come from space. In the new study, scientists analysed the samples with electron microscopy and found that the surface of these tiny rock fragments was covered with minerals composed of iron and nitrogen.

Scientists had long suspected that these building blocks came from meteorites that struck the planet in its early history. However, the evidence was not as strong.

"We propose that small meteorites called micrometeorites, which contain ammonia compounds, broke off from icy celestial bodies and collided with Ryugu," said Toru Matsumoto, lead author of the study:

Micrometeorite collisions trigger chemical reactions on the iron-coated surface and lead to the formation of iron nitrate. Hayabusa 2 collected these samples of Ryugu in February 2019. The samples were brought to Earth in December 2020 and made available for examination in Japan in 2021.