Chinese and International Researchers Identify Nitrogen-Bearing Organics in Chang'e-5 and Chang'e-6 Lunar Samples

An international research team led by experts from the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS) has published an analysis of lunar regolith returned by the Chang'e-5 and Chang'e-6 missions. The data were released in the journal Science Advances on April 8 or 9, 2026. This study marks the first systematic identification of diverse nitrogen-bearing organic compounds in lunar dust and describes their evolutionary trajectory within the Solar System environment.

Due to its geologically inert environment, the Moon preserves chemical archives that have been erased by active processes on Earth. This research confirms that the Moon records a history of organic matter delivered to the inner Solar System by asteroids and comets. The organic compounds primarily appear as sub-micron to micron-sized grains, as well as surface coatings and encapsulated structures composed of carbon, nitrogen, and oxygen. Amide functional groups were detected in some samples, indicating complex chemical reorganization.

Isotopic profiling conducted via NanoSIMS served as a critical component of the study. The researchers found that isotopic ratios for hydrogen, carbon, and nitrogen in the lunar organics are, on average, "lighter" than those typically found in carbonaceous chondrites and other asteroid samples. This discrepancy supports a scenario in which the parent material underwent evaporation and subsequent condensation during high-temperature impact events.

For the first time, scientists have documented clear evidence of solar wind implantation within the organic matter. This serves as a reliable "fingerprint" to rule out terrestrial contamination and confirms that the material remained on the lunar surface for an extended period, where it was subjected to irradiation. In the early Solar System, asteroids and comets delivered essential building blocks for life—such as carbon, nitrogen, oxygen, phosphorus, and sulfur—to the terrestrial planets, where they likely acted as chemical precursors.

The Chang'e-6 mission, which launched on May 3, 2024, returned 1,935.3 grams of material from the far side of the Moon, significantly expanding the research database provided by its predecessor, Chang'e-5. These findings establish an analytical framework for future interplanetary sample-return missions, including the planned Tianwen-2 mission, by providing insights into the transformation of materials from small celestial bodies in the early Solar System.