An international research team has identified multiple nitrogen‑bearing organic compounds in lunar soil returned by China’s Chang’e‑5 and Chang’e‑6 missions, offering new clues about how organic matter evolved in the early solar system, China Science Daily reported.
The study, led by the Institute of Geology and Geophysics at the Chinese Academy of Sciences with partners in the United States and China, marks the first systematic identification of such compounds on the surfaces of lunar soil grains.
Researchers said the findings show the Moon preserves evidence of organic material delivered by asteroids and comets, as well as how those materials were later altered by impacts and radiation on an airless body. Because geological and biological activity on Earth has erased most early records, the Moon serves as a more stable archive.
Using a range of microscopic and spectroscopic techniques, the team analyzed grains from the Chang’e missions and found that hydrogen, carbon and nitrogen isotopes in the lunar organics are generally lighter than those in carbonaceous chondrites. The signatures point to evaporation, condensation and redeposition caused by impact events.
The study also identified signs of solar‑wind implantation in lunar organics for the first time. Variations in hydrogen isotopes and H/C ratios near grain surfaces suggest prolonged exposure to solar‑wind irradiation. Corresponding author Hao Jialong said the signatures help rule out terrestrial contamination.
Researchers said the work provides technical and scientific support for future deep‑space sample‑return missions, including Tianwen‑2, by establishing an analytical framework for studying microscale organic matter.
The findings outline an evolutionary sequence for lunar organics — from delivery by impacts to restructuring and space‑weathering — offering new insight into the history of organic material in the early solar system.
The study was published Thursday in Science Advances.