Cosmochemistry is the study of the chemical composition and processes of celestial bodies, including planets, moons, asteroids, and comets. It combines principles from chemistry, astronomy, and geology to understand the origins and evolution of these objects in the universe. Researchers analyze samples from space missions and meteorites to uncover the building blocks of the solar system. This field also explores the formation of elements and compounds in stars and during cosmic events, such as supernovae. By studying isotopes and chemical signatures, cosmochemists can gain insights into the conditions that existed in the early universe and the processes that shaped our solar system, including the role of nuclear fusion and stellar nucleosynthesis.