4.9% ordinary matter

68.3% Supernova evidence

Key evidence for dark energy comes from Type 1a supernovae – collapsing stars that always reach the same peak brightness.

Expansion curves

The nature of dark energy affects whether expansion of the universe reverses, continues or speeds up.

Heading for a Big Rip?

The effects of dark energy seem to have grown stronger. If this continues, cosmic acceleration could tear everything apart.

Alternatives

Some cosmologists think evidence for dark energy could be explained by modifications to known theories of gravity.

26.8% Missing mass

In the 1930s, Fritz Zwicky first identified huge amounts of dark matter through the motion of galaxies within clusters.

Galactic rotation

In the 1970s, astronomers found that the gravity of this unseen matter also affects the orbits of stars in galaxies.

Planets or particles?

Some dark matter is probably ‘normal’ dense, non-luminous objects like planets, brown dwarfs or black holes.

Gravitational lensing

We can trace dark matter by measuring the way galaxy clusters warp and deflect light from more distant objects.