The Earth forms from the protoplanetary disk around the young sun through the accretion of rock and dust.
A Mars-sized object, named Theia, collides with the young Earth, and the debris forms the Moon.
Following the giant impact, debris coalesces into the Moon while Earth's surface remains a molten ocean of magma that gradually begins to cool.
As the planet cools sufficiently, water vapor condenses and, combined with cometary and volcanic water, forms the first liquid oceans on Earth's surface.
A period of intense asteroid and comet impacts pummels the inner solar system, including Earth, delivering water and organic molecules while also sterilizing surface environments.
The first simple, self-replicating organisms arise in the oceans of the young Earth.
Early microbial life evolves the ability to capture sunlight and convert it into chemical energy, laying the groundwork for a fundamentally new metabolism.
Cyanobacteria evolve the capacity for oxygenic photosynthesis, splitting water molecules and releasing oxygen as a byproduct for the first time.
Dissolved iron in the oceans reacts with newly produced oxygen, precipitating out as iron oxide layers on the seafloor over vast spans of time.
Photosynthetic cyanobacteria saturate the atmosphere with oxygen, causing a mass extinction of anaerobic organisms.
Earth plunges into one of the most severe ice ages in its history, likely triggered by the collapse of methane greenhouse gases following the rise of atmospheric oxygen.
Complex cells with internal membrane-bound structures, including a nucleus, begin to emerge, likely through symbiotic mergers of simpler prokaryotic organisms.
Earth enters a long stretch of remarkable environmental and evolutionary stasis, with atmospheric oxygen and ocean chemistry remaining relatively stable for roughly a billion years.
Complex cells with membrane-bound nuclei and organelles evolve, likely through the endosymbiotic incorporation of mitochondria into a host cell.
Oxygen levels stabilize in the atmosphere and oceans, allowing aerobic respiration to flourish among early eukaryotes.
Earth's landmasses assemble into one of the first recognized supercontinents, Columbia, also known as Nuna.
Early eukaryotic organisms evolve sexual reproduction, dramatically increasing genetic diversity and accelerating evolutionary change.
The supercontinent Rodinia assembles and later fragments, dramatically reshaping ocean currents, climate, and nutrient cycles in ways that set the stage for the diversification of complex life.
An explosive diversification of multicellular life takes place, giving rise to most modern animal groups.
A massive diversification of marine life fills the oceans with new species of trilobites, brachiopods, and early coral reefs.
Simple plants, related to modern mosses and liverworts, begin to establish themselves on land, transforming barren continents.
Jawed fish diversify dramatically in the seas while the first true forests, with tall trees like Archaeopteris, spread across the continents.
The most severe mass extinction in Earth's history wipes out roughly 90 percent of marine species and 70 percent of terrestrial vertebrates.
Following the Triassic-Jurassic extinction event, dinosaurs diversify rapidly and become the dominant terrestrial vertebrates for over 130 million years.
A massive asteroid impact near present-day Mexico causes a mass extinction, including that of the non-avian dinosaurs.
Homo sapiens emerges in Africa and later begins to spread across the entire world.
Human activity becomes the dominant force influencing the Earth's climate and ecosystems.
After centuries of climate fluctuations, the Earth may return to a natural glacial cycle, with extensive ice sheets at northern latitudes.
Continents have shifted slightly due to plate tectonics, evolution has produced new species, and life -including possibly humans- has adapted to a drastically changed planet.
This catastrophic collision hurls enormous amounts of molten rock into space, which gradually coalesces into our Moon. The impact may also have tilted the Earth's rotational axis and accelerated its spin rate. Without this event, the Earth would have had a very different orbit, day-night cycle and tidal action, which had a crucial influence on the later emergence of life.