Microanalysis Techniques Guarantee Long-Term Research On Chang’e-5 Lunar Samples

Abstract

Humans have successfully returned samples from the Moon ten times. Sample return missions have two advantages. First, we can carry out high-resolution and high-precision measurements of returned samples using state-of-the-art technologies in the laboratory. Second, the returned samples can support ongoing research for decades or centuries. The same sample can continuously “tell new stories” with the advancement of technology. On July 12, 2021, the allocation of the first batch of Chang'e-5 lunar samples quickly ignited a research bonanza for lunar and planetary sciences in China. State-of-the-art microanalysis techniques have played important roles in both scientific research and the artistic creation of lunar samples. For example, the combination of micro-X-ray fluorescence (μXRF), 3D X-ray microscopy (XRM), and scanning electron microscopy the rapid screening and positioning of Zr-bearing minerals for U-Pb dating. The high spatial resolution U-Pb dating method by secondary ion mass spectrometry it possible to determine the crystallization age of tiny (< tomography; 27 (4) trace element analyses by instrumental neutron activation analysis; 28 (5) high-resolution Cl isotope analyses by NanoSIMS 29 and high-precision C isotope analyses by SIMS; 30 (6) combined separation for high-precision iron, calcium, and magnesium isotope analyses; 31 (7) measurements of thermal-induced alterations by in situ TEM heating; 32 and (8) identification of lunar highland clasts in CE-5 breccias by TIMA-SEM-EPMA.