The accurate radiometric calibration is very important for remote sensing optical sensors. Numerous astronomical measurements and model analyses have shown that the Moon is extremely stable in reflectance properties and can serve as a great absolute reference source. Jilin-1 satellite has made long-period observations of the Moon over a wide range of phase angles. However, the spectra displayed fluctuations after radiometric calibration with the provided coefficients. This is inconsistent with the lunar reflectance spectra, which are smooth and generally no sharp absorption. In this study, we conducted radiometric calibration for PMS2 onboard Jilin-1 Guangpu02 (GP02) satellite using the Moon as the calibration source. The calibration results were validated based on different lunar geological terrain, i.e., maria and highlands. The lunar phase curve obtained through the application of the lunar calibration coefficients derived in this study show good agreement with the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and PLEIADES data. The results indicate that: (1) the spectra become much smoother after lunar calibration, consistent with the characteristics of lunar spectra; (2) the lunar calibration results demonstrate exceeding linearity, with average linear fit uncertainty of 0.69% and goodness-of-fit ( R ² ) of 0.9997 for the calibration coefficients; (3) the average relative difference between the phase curves of PMS2 and SeaWiFS is 3.6% and 4.66% with PLEIADES. The obtained results confirm the effectiveness of our lunar calibration method. Although this method was specifically applied to the PMS2, the lunar calibration method is expected to be applicable to other Earth-orbiting satellites.

The development of high-efficiency thermal insulation materials is crucial for terrestrial and space applications under extreme conditions. Synthetic aerogels, featuring porosities up to 99%, can reach the values of ~10 mW m ⁻¹ K ⁻¹ under vacuum. However, whether natural materials can achieve this performance remains an open question. Here, we report lunar agglutinates from the Chang’E-5 mission that exhibit thermal conductivities as low as ~8 mW m ^{− 1} K ^{− 1} under vacuum, surpassing most high-performance aerogel materials — at modest porosities of only 7–30%. Integrated structural characterizations and atomic-to-mesoscale simulations demonstrate that the space-weathering-forged multiscale voids and multiphase interfaces collaboratively suppress phonon transport within agglutinate particles, leading to their ultra-low thermal conductivities. These natural structures demonstrate a non-porosity-dominated thermal insulation mechanism. The findings redefine the microstructural design principles for super-insulating materials and provide a particle-scale explanation for the ultralow thermal conductivity of lunar regolith.

Lunar soils record the history and spectral changes resulting from the space-weathering process. The solar wind and micrometeoroids are the main space-weathering agents leading to darkening (decreasing albedo) and reddening (increasing reflectance with longer wavelength) of visible and near-infrared spectra. Nevertheless, their relative contributions are not well constrained and understood. In this study, we examine the near-infrared spectral variation as a function of lunar latitude and chemical composition using remote spectroscopic analysis of mare basalts and swirl regions. The results indicate that the reflectance of lunar mature soils darkens and the spectral slope flattens (reddening effect saturation) in areas of enhanced solar wind flux. We propose a previously unrecognized stage of space weathering (the post-mature stage), in which solar wind implantation may contribute to the growth and coarsening of metallic iron particles into larger microphase iron. This space-weathering mechanism is dominated by the solar wind and has important implications for understanding the alteration processes of airless bodies across our solar system.