Nitrogen, which played a major role in the formation of life on Earth, may have come from asteroids

An international team led by Kyoto University in Japan may have discovered where nitrogen, which plays a major role in the formation of life on Earth, comes from.

According to the new study published in Nature Astronomy, small meteorites that broke away from icy celestial bodies in the outer region of the Solar System carried nitrogen to regions close to the Earth in the first days of its formation.

“Our findings raise the possibility that greater amounts of nitrogen compounds than previously realized were transported closer to Earth and served as the building blocks of life on our planet,” said Hope Ishii, one of the research team.

RNA has previously been found on the Ryugu asteroid

Scientists reached this conclusion by analyzing samples from the Ryugu asteroid. An RNA component and vitamin B3 were recently discovered in samples collected from Ryugu by the Japan Space Agency’s Hayabusa 2 spacecraft. Apart from these, other biological molecules were also found, including amino acids, amines and carboxyl acids, which are the building blocks of proteins.

The discovery of RNA is seen as the strongest evidence yet that the organic building blocks that enabled life on Earth came from space.

Scientists, who examined the collected samples with an electron microscope, found that the surface of the rock pieces was covered with minerals consisting of iron and nitrogen. Scientists have long suspected that these building blocks came from meteorites that hit the Earth in the early days of the planet. However, the available evidence was not that strong.

Toru Matsumuto, lead author of the study, said: “We suggest that small meteorites called micrometeorites, which contain ammonia compounds, broke away from icy celestial bodies and collided with Ryugu. Micrometeorite collisions trigger chemical reactions on the iron-covered surface and lead to the formation of iron nitrate.” He said his words.

Hayabusa 2 collected these samples of Ryugu in February 2019. The samples were brought to Earth in December 2020 and became available for examination in Japan in 2021.