Most of the atoms in your body likely spent millions of years circling the Milky Way on a cosmic "conveyor belt" before returning to our galaxy prior to the solar system's creation, a new study suggests.
Most elements in the universe, except for hydrogen and helium (and a few other weird exceptions), were forged by stars, either through nuclear fusion deep within their cores or during gigantic stellar explosions, known as supernovas. These explosions also disperse the newly forged materials into interstellar space. The matter then forms giant clouds that eventually condense into new stars surrounded by other objects, such as planets, moons, asteroids, comets — and in Earth's case, people.
