Astromineralogy

Astromineralogy is the study of the mineral content, composition, and textures of extraterrestrial materials. It aims to understand how minerals form in stars and the interstellar medium, how they condense in the early solar nebula, and how space weathering alters them. By analyzing meteorites, interplanetary dust particles, cometary grains, and returned samples, astromineralogists reconstruct stellar sources, condensation sequences, and alteration histories.

Key materials include presolar grains such as silicon carbide, graphite, diamond, corundum, and spinel embedded in primitive meteorites, as well as calcium-aluminum-rich inclusions (CAIs). Minerals common in solar-system materials include olivine, pyroxene, magnetite, sulfides, phyllosilicates, and various oxides. Presolar grains exhibit isotopic signatures that reveal origins in asymptotic giant-branch stars or supernovae. Meteorites and IDPs also record aqueous and thermal alteration, cosmic-ray exposure, and solar-wind modifications.

Standard methods involve electron microscopy (SEM/TEM), electron-probe analysis, mass spectrometry (incl. isotope-ratio and noble gas analyses), X-ray diffraction, and vibrational spectroscopy (Raman, infrared). Microbeam techniques such as SIMS and NanoSIMS enable in-situ isotopic measurements at submicron scales.

Significance: astromineralogy links stellar evolution to planetary formation, constrains conditions in the early solar system, and informs interpretation of remote sensing data for asteroids and comets. It guides the selection and analysis of samples from future missions and contributes to understanding mineral resources for space exploration.