Nitrogen is a fundamental element for the biomolecules that underlie life on Earth. Yet in its unbound gaseous state it tends to escape into space rather than lock into solid materials, making it challenging for astronomers to trace its delivery to our planet from the early solar system.
The Hayabusa2 mission returned surface material from the asteroid Ryugu to Earth for detailed laboratory study. Scientists focused on the fine dust grains covering the asteroid, using advanced spectroscopic techniques to search for nitrogen bound within various molecular structures.
The findings indicate that while nitrogen is initially present mostly as free gas, it can gradually become incorporated into more complex organic molecules over extended periods. This process likely involves reactions with carbon‑rich compounds also found in the dust, leading to the formation of nitrogen‑bearing organics.
These results provide important clues about how bio‑essential elements like nitrogen were made available in the early solar system. They support the notion that asteroids such as Ryugu could have acted as carriers of pre‑formed organic material, slowly building up complex molecules in space that were later released upon impact with the young Earth.