Space Weathering of the Chang'e-5 Lunar Sample From a Mid-High Latitude Region on the Moon

Micrometeorite impacts and solar wind irradiation, the dominant space weathering (SW) processes, largely modified compositions and microtexture of soil materials on the Moon. Here, we report the SW characteristics of the Chang'e-5 lunar soils from mid-high latitude (43.06 degrees N). All mineral phases exposed on the surface of a single basalt clast have a vapor deposit layer, whereas the textures of the solar wind irradiation-damaged zone are dependent on the host mineral species. Nanophase Fe (npFe(0)) particles are spherical in the amorphized zone of pyroxenes, elongated in ilmenite, and irregular on the jagged surface of iron sulfide, but not found in Fe-poor merrillite. Vesicles were found in the damaged zone of ilmenite and merrillite, but with different shapes. The observations were compared to Apollo samples and demonstrate no significant altitude-dependent effects on the SW, which is important for decoding the reflectance spectra of the Moon.

Automated summary

This study reports the characteristics of space weathering on lunar soils collected by Chang'e-5, showing that micrometeorite impacts and solar wind irradiation have significantly modified the composition and microstructure of the lunar soil materials. The exposed mineral phases on the surface of a basalt clast have a vapor deposit layer, and the textures of the solar wind irradiation-damaged zone vary depending on the host mineral species. The findings contribute to the understanding of the reflectance spectra of the Moon.