From the primordial clouds of hydrogen and helium, the very first stars form, the building blocks of what will later become the Milky Way.
Ancient globular star clusters and the first protogalactic structures form the halo around the emerging Milky Way galaxy.
A dwarf galaxy collides with the young Milky Way and accelerates the formation of the thick disk and the structured halo.
The Milky Way develops its characteristic spiral arms as gas condenses into new generations of stars.
A molecular cloud collapses, possibly triggered by a nearby supernova, forming the core of our future solar system.
From colliding planetesimals in the protoplanetary disk, the young Earth gradually grows.
A Mars-sized object called Theia collides with the early Earth, leading to the formation of the Moon.
The increasing brightness of the aging Sun begins to drastically disrupt the Earth's climate systems.
The Milky Way and the Andromeda Nebula merge into one enormous elliptical galaxy, after billions of years of approaching each other.
The Sun swells into a red giant and may engulf the inner planets, including a scorched, unrecognizable Earth.
Astronomers discovered, via the Gaia satellite, traces of an ancient, massive dwarf galaxy – named Gaia-Enceladus – that merged with the Milky Way some ten to eleven billion years ago. This cosmic collision thoroughly stirred up the young stellar population, injected new gas, and set in motion the formation of the thick galactic disk. Traces of this merger can still be found in the eccentric orbits of old stars.