- Eugene Ionesco
Most of the atoms in our body once existed inside a star.
The elements in our bodies, and all the other life forms on our planet, and the elements that make up the Sun and all the places in our solar system – they were all created long before we were even a dim glow in a cloud of gas and dust.
So, where did those elements come from?
Let’s start with hydrogen – it’s the most plentiful. And it’s what stars are made of. All the hydrogen in the universe was created during the Big Bang – the event that began the universe almost 14 billion years ago.
Hydrogen combines easily with other elements. When it joins with oxygen — it makes H2O – water – which we know is essential for life. In fact, WE are mostly water. Our skin, organs, muscles, bones, and nerves basically give the water a place to hang out.
The other elements in our bodies – the calcium in our bones, the iron in our blood, the carbon molecules that are the underpinnings of proteins and amino acids – those were all cooked up inside stars that died long before the solar system ever formed.
So, in a sense, we – and everything we see around us – are made up of the ashes of old, dead stars.
Science Writer Carolyn Collins Petersen - Astronomy Podcast
This planetary-nebula process spreads elements like carbon, and nitrogen, and oxygen out to space. But, what about the heavier elements like magnesium and silicon, iron, nickel, gold, and uranium? Those are created in stars much more massive than the Sun as they age and die.