Big Bang

The Big Bang (0.000000000000000000000000000000000001 secs)

99,999 BCE

The universe began with an explosion that started space and time. This may have been caused by "inflation," in which energy that existed in the vacuum of space was suddenly mobilized.

Expansion of the universe (1 second after)

99,998 BCE

The universe expands slowly and gravity forms. The nuclei of atoms are held together followed by electromagnetic forces. The universe is now made up of particles, quarks, electrons, photons and neutrons.

Elements form (3 seconds after)

99,997 BCE

Photons and neutrons come together to form the nuclei of elements such as hydrogen and helium.

The universe begins to cool down (500,000 years after)

99,996 BCE

The universe consisted of a hot expanding gas. It eventually cooled down to allow electrons to combine with hydrogen and helium. Photons are turned into microwave wavelengths which are cosmic background radiation we see today.

Galaxies form (1,000,000,000 years after)

99,995 BCE

Gravity pulled pockets of gas together and made it more dense. This gas was then ignited under the influence of gravity and density, forming the earliest stars and galaxies.

Era of Quasars (3,000,000,000 years after)

99,994 BCE

Small galaxies are combined to make bigger ones, forming elliptical galaxies. It was typically violent, stars and gas collapsed to form black holes. It was hot enough that light can be seen before it disappeared. This is known as a quasar

Supernovas form (6,000,000,000 years after)

99,993 BCE

Stars were born inside galaxies and others exploded. These explosions were called supernovae, providing oxygen, carbon, nitrogen, calcium and iron. Other elements were formed such as gold, silver, lead and uranium.

The Sun is formed (5,000,000,000 years before the present)

99,992 BCE

A cloud of gas inside the Milky Way formed into the Sun under immense gravity. Gas and debris were formed into a disc around it, creating planets, moons and asteroids.