Edwin Hubble Showed the Universe Is Expanding

Discovered in 1965 by Arno Penzias and Robert Wilson, it dates from about 380,000 years after the Big Bang.

Roughly 27% is dark matter and about 68% is dark energy.

Scientists estimate this age by measuring the cosmic microwave background and the expansion rate.

Although the universe is about 13.8 billion years old, its expansion means the observable region is much larger than that age suggests.