Cosmochemical

Cosmochemical is an adjective referring to cosmochemistry, the scientific study of the chemical composition of matter in the universe and the processes that shape it. It sits at the intersection of astronomy, geology, and chemistry, and it centers on materials from space—such as meteorites, lunar and planetary rocks, and stardust—and on the isotopic and elemental signatures they bear.

Researchers aim to understand the origins and evolution of the solar system, stars, and galaxies by analyzing abundances and isotope ratios. Major topics include the composition of primitive solar system materials (for example, chondrites and calcium-aluminum-rich inclusions), nucleosynthetic signatures in presolar grains, isotopic anomalies, and the timing of formation events inferred from radiometric dating. Cosmochemical data illuminate how chemical elements were produced, distributed, and incorporated into planetary bodies.

Methods commonly used include mass spectrometry (including TIMS, SIMS, and ICP-MS), spectroscopy, and careful chemical separations. Analysts study tiny samples, sometimes down to nanogram scales, to determine elemental abundances and isotope ratios. Diagnostic tools such as the three-isotope plot for oxygen and other multi-isotope systematics help distinguish solar system processes from stellar nucleosynthesis.

Cosmochemistry is closely related to but distinct from cosmology and planetary geology. Its findings inform models of solar system formation, planetary differentiation, and galactic chemical evolution, and they complement observations from astronomical surveys and space missions that return samples or observe remote objects.