The most mindblowing thing that astronomy tells us is that we are made of stardust. The nitrogen in your DNA, the iron in your blood, and the calcium in your bones were once produced in the core of a giant star. But how is that possible? Well, soon after the universe was born, primordial nucleosynthesis created only two major chemical elements; hydrogen and helium. The first generation of stars formed from these elements and fused heavier ones in their core. When these stars died during a supernova, they enriched the interstellar medium with heavier elements such as oxygen, carbon, iron, etc. From that enriched medium, subsequent generations of stars formed. The Sun is a third-generation star relatively rich in heavy elements compared to its ancestors. So most of the elements on Earth and inside us were once produced by stars. We are literally made of star stuff. #astronomy #space #universe #physics #stars #chemistry