What primarily creates elements heavier than iron in the universe?

The formation of elements heavier than iron is primarily achieved through the process of supernova explosions from massive stars. In the lifecycle of a massive star, it undergoes a series of nuclear fusion reactions in its core, which produces lighter elements. However, as the star evolves and begins to fuse heavier elements, it reaches a point where iron is produced.

Iron itself cannot release energy through fusion, leading to a build-up in the core. When the core becomes unstable, the star eventually undergoes a catastrophic collapse, resulting in a supernova explosion. During this explosive event, the extreme temperatures and pressures allow for nuclear reactions that can produce a wide range of heavier elements, including elements like gold, uranium, and lead. These elements are then expelled into space, enriching the surrounding interstellar medium, which eventually contributes to the formation of new stars, planets, and other celestial bodies.

Other processes, such as planetary formation, the continuous fusion within sun-like stars, and chemical reactions in nebulae, play roles in the universe but do not primarily account for the creation of elements heavier than iron. Planetary formation deals more with the accumulation of existing material rather than the creation of new elements. Sun-like stars largely produce elements up to iron through fusion but do not