Title worded awkwardly, but I was thinking about the chemical makeup of our planet, and the other bodies in our solar system. Is the chemical makeup of our star system similar to every other star system? And if not, are we more similar to stars nearest to ours? Is it totally random? Like does every star system have roughly the same amount of iron, hydrogen, oxygen, etc. When averaged out? Has this even been studied?
yeah, we basically know the chemical composition of other stars from their emission lines (every chemical emits light at specific frequencies, depending on the atom type). and so we know that most matter in the universe (at least in the brightly visible stars’ outer layer) is hydrogen, followed by helium, which make up 99% of the mass. the rest is all other elements combined.