What is the universe made of?

Abstract

From observations of dynamics of galaxy, galaxy cluster and the universe as a whole, astronomers found that most matter in the universe does not emit light and is therefore dark. Dark matter accounts for 27% of the total matter and energy budget of the universe. Dark energy accounts for 68%. Ordinary matter that can be explained by the standard model of particle physics only accounts for 5%. Dark matter and dark energy are among major discoveries of physics and astronomy, and are a major research frontier. We review the discovery of dark matter and dark energy, explain their basic known properties and address some unresolved problems.