Question: What is the universe made of?

Kerrianne Harrington answered on 8 Nov 2017:

Mostly dark matter and dark energy, with some atoms (the building blocks of stars, planets and ourselves)! Dark matter doesn’t emit light, so we haven’t seen it, but we know it is there from the effect it has on stuff we can see in space. Dark energy is even more mysterious! So there’s actually still a lot we don’t know about what makes up the universe!