We May All Be Made of Stardust, But What Makes Stardust?
Most of my followers should know that the atoms that comprise your body and just about everything around you were forged in stars. If you didn’t know this I urge you to spend more time avidly watching Cosmos.
But how does this process actually occur? The secret lies in nuclear fusion which is essentially the opposite to fission (which causes radioactive decay). Fusion is simply the combination of two nuclei into one larger nuclei. In the process a large amount of energy is released. The energy that is released is what powers stars and gives you sunlight. The cornerstone of this process lies in a property called binding energy, which is essentially the energy that holds together an atom’s nucleus. The important thing is to relate this to the mass of nucleus by referring to it as "binding energy per nucleon" (protons and neutrons essentially). Of all the elements iron has the highest binding energy per nucleon which means that combining atoms smaller than iron releases energy, whilst combining atoms that are larger requires an energy input. Heavier elements than iron are typically only produced during supernovas (a remnant of which is pictured above) which also have the effect of distributing the atoms in shells or jets.