Fig. 1: Water content and hydrogen isotope composition of lunar grains.
From: Chang’E-5 samples reveal high water content in lunar minerals
a–c Reflectance infrared spectra of a olivine, b plagioclase, and c pyroxene. Points of analysis for NanoSIMS measurements are marked on the backscattered electron images (each point of analysis is marked with the same color as that used for depicting the spectra and the numbers correspond to the water content and δD). The scale bar is 10 nm. The solid lines are smoothed spectra obtained using the Fast Fourier Transform algorithm, and different colors of the solid lines represent different samples; the dashed lines indicate the baseline reflectance of absorption peaks. d δD versus H2O plots of lunar minerals. δD = {[(D/H)sample/(D/H)VSMOW] − 1} × 1000; VSMOW Vienna standard mean ocean water19. The round dots represent δD and water content of olivine, the square dots represent that of plagioclase, and the triangular dots represent that of pyroxene. The error bars (gray line) represent 2σ. The difference in water content from reflection infrared and NanoSIMS is mainly attributed to the difference in measurement depth; for details, see Methods.
