Question

Describe the structure and composition of the universe

Answer 1

Today astronomers believe that around one quarter of the mass-energy of the Universe consists of dark matter. This is a substance quite different from the normal matter that makes up atoms and the familiar world around us.

Answer 2

$Composition$

The universe is composed almost completely of dark energy, dark matter, and ordinary matter. Other contents are electromagnetic radiation (estimated to constitute from 0.005% to close to 0.01% of the total mass-energy of the universe) and antimatter.