Question

what kind of small object composes much of the universe

Answer 1

It’s thought that most of the mass in the universe can’t actually be seen – it’s called Dark Matter.

We see matter in the universe because of its ability to reflect or absorb light, or emit or absorb radiation of some kind. But Dark Matter doesn’t do any of this! We only think that it’s there because the matter than we CAN see (from every atom to a planet) cannot create all of the gravitational pulls that we see in the universe. Physicists realised that there must be more matter that we can’t see to be causing such big forces. They think that 84.5% of the matter in the universe is Dark Matter.