Astronomy
Stellar Nucleosynthesis
Quick fact
Stars convert hydrogen into heavier elements through fusion; the process stops at iron because fusing iron consumes energy rather than releasing it. Elements heavier than iron require explosive events like supernovae or neutron star collisions.
Why this is interesting
Every atom of carbon in your body, every molecule of oxygen you breathe, and the iron in your blood were created deep inside a star that lived and died long before the Sun was born. How does a star turn simple hydrogen into the rich variety of elements that make up our world?