The latest study, titled "Influx of nitrogen-rich material from the outer Solar System indicated by iron nitride in Ryugu samples," explores the intriguing possibility that the nitrogen compounds transported near Earth, particularly ammonium salts, played a crucial role in the formation of life on our planet.
Utilizing electron microscopy, researchers closely examined Ryugu samples, revealing tiny minerals composed of iron and nitrogen (iron nitride: Fe4N) on their surfaces. The breakthrough came when the scientists proposed that micrometeorites, carrying ammonia compounds, collided with Ryugu.
1 December 2023, 22:34 GMT
These collisions triggered chemical reactions on magnetite, a key component of the asteroid's composition, leading to the formation of iron nitride.
Lead author Toru Matsumoto, an assistant professor at Kyoto University, explained that the iron nitride was observed on the surface of magnetite, which undergoes changes when exposed to the harsh space environment.
The loss of oxygen atoms from the magnetite's surface, caused by solar wind and micrometeorite impact, results in the formation of metallic iron. This iron readily reacts with ammonia, creating ideal conditions for the synthesis of iron nitride.
"Our recent findings suggest the possibility that a greater amount of nitrogen compounds than previously recognized was transported near Earth, potentially serving as building blocks for life on our planet," states Hope Ishii, co-author and affiliate faculty at the University of Hawai'i at Mānoa.
The findings were published in Nature Astronomy journal.