Solar Flare Tracks: Unveiling Features and Their Impact on Distinct Lunar Soil Transformations

Studying crystal defects is essential for understanding a material's origin, evolution, and behavior. Lunar materials can exhibit defects from space weathering including high-energy ion implantations, which rarely happens on Earth. Investigating the variation in defects’ structure along the direction of implantation and its impact on lunar materials’ transformation is vital, but unfortunately, this remains unclear. Using multi-scale, 3D characterization of lunar olivine from Chang'e-5 mission, it is found that solar flare tracks, common lunar defects induced by implantation, have a “near-linear” structure. These tracks show varied shuffling of oxygen and silicon atoms and vacancies along the traces. Intriguingly, the in situ electron microscopy heating experiments, detected for the first time that the evolution of solar flare tracks leads to the generation of iron nanoparticles and the release of oxygen upon heating. This reaction is rarely observed on Earth and unreported on the Moon before, which produces resources that can be harnessed for future human exploration and the establishment of lunar habitats.