Space Trivia : Composition of the universe
As for the substance in the universe, we recall galaxy, stars as a big one and the drifting gas.
These are so-called common substance made of atoms.
Neutrino which does not constitute atoms is also found in the universe.
The ratio that the substance which we have already discovered including atoms and neutrino occupies in the cosmos is only 5%.
95% is still remain unknown and those are called Dark matter/energy.
