We Are Made of the Rarest Material in the Universe: Stardust
Stardust is a name for the heavy atoms created inside stars and blown out as dust as the stars age and die, to drift through space. Stardust represents only one-hundredth of one percent of the density of the universe but 90% of the weight of each one of us. All the atomic matter in the universe makes up about four and a half percent of the cosmic density, but most of this material is invisible. All the stars and glowing gas that light up the night sky represent only about half a percent of the cosmic density. The rest of the universe is mainly non-atomic dark matter (23%) and dark energy (72%). If you never learned this in school, it’s because the composition of the universe has only been known since 1998.