Read this history as plain text
The whole history, in brief
4.54 billion years ago · approximate date
Earth takes shape
Earth grew from the disc of rock and gas circling the early Sun. Impacts and the decay of radioactive elements kept it so hot that the surface stayed molten and no water could last.
4.51 billion years ago · approximate date
The Moon is born
The leading explanation for the Moon is a giant impact within Earth's first hundred million years. A body roughly the size of Mars collided with the young planet, and the ejected material settled into orbit and drew together as the Moon.
4.4 billion years ago · approximate date
The first oceans
As the crust cooled, water from volcanic gas and impacts could stay liquid at the surface. Zircon crystals of this age carry a chemical signature that points to liquid water, though how much of it there was, and whether it formed true oceans, is still argued over.
3.7 billion years ago · approximate date
The first life
Rocks of about this age carry chemical and structural marks that many researchers read as traces of life, though the oldest of those claims are disputed. Firmer evidence appears by about 3.5 billion years ago. Either way the organisms were single celled and microscopic.
2.4 billion years ago · approximate date
Oxygen changes everything
Microbes that made their energy from sunlight released oxygen as waste. It built up over hundreds of millions of years, rusting iron out of the oceans and changing the atmosphere for good. This is the Great Oxidation Event.
1.8 billion years ago · approximate date
The first complex cells
Larger cells with internal structure, the eukaryotes, emerged when one microbe came to live inside another. Every plant, animal and fungus descends from that partnership, though new fossils keep moving the date.
1 billion years ago · approximate date
Many cells become one
Groups of cells started to specialise and live as a single body. They were soft and simple, and left few fossils, so the earliest dates keep moving as new ones are found.
538 million years ago · approximate date
The Cambrian explosion
Near the base of the Cambrian, the oceans filled with animals carrying shells, eyes and limbs. Most of the major branches of the animal kingdom trace back to this stretch of time.
470 million years ago · approximate date
Life reaches land
Simple plants spread from the water onto rock and soil, slowly greening the continents. Their roots and decay built the first soils, and animals soon followed them out of the sea.
230 million years ago · approximate date
The first dinosaurs
Dinosaurs arose in the Triassic and held the land for about 164 million years, far longer than mammals have managed so far. They ranged from small runners to the largest animals ever to walk on land.
210 million years ago · approximate date
The first mammals
The earliest mammals were small and mostly nocturnal. Fur, milk and adaptable teeth were already in place, and would matter a great deal once the dinosaurs were gone.
66 million years ago
The great extinction
A large asteroid struck the Earth and, together with intense volcanism, drove a mass extinction that erased every dinosaur except the birds. Small mammals were among the survivors.
7 million years ago · approximate date
The first hominins
Around this time the human branch split from the ancestors of chimpanzees. The earliest hominins were apelike, but had begun to stand and walk differently. The split is dated from genetics and fossils, and stays uncertain by a million years or more.
2.8 million years ago · approximate date
The genus Homo
The genus Homo appears in the fossil record of Africa, with a larger brain and a growing reliance on tools that followed soon after. Several human species would live, and often overlap, across the following millions of years.
300,000 years ago · approximate date
Homo sapiens
Homo sapiens evolved in Africa during a long stretch of repeated climate swings. Earth had already lived through more than 99.99 percent of its history before we arrived.
12,000 years ago · approximate date
Farming begins
As the last ice age ended, communities in several regions began to farm plants and keep animals. Settled life allowed populations to grow and made cities and writing possible.
6,000 years ago · approximate date
The first cities
In fertile river valleys, villages grew into cities of thousands of people, with shared temples, markets and rulers. Living at that density called for records, and the first accounting marks followed within a few centuries.
5,300 years ago · approximate date
Writing is invented
The earliest writing began as a way to track goods and trade, then grew to record law, story and belief. With writing, knowledge could outlive the person who held it.
4,500 years ago · approximate date
The pyramids of Giza
The great pyramids were built as royal tombs, cut and hauled by hand over about two decades. The Great Pyramid is the oldest of the seven wonders of the ancient world and the only one still standing.
2,030 years ago · approximate date
The start of the common era
The estimated birth of Jesus, placed by most historians between about 6 and 4 BCE, later became the anchor for a widely used calendar. It is an estimate rather than a precise year, and there is no year zero.
250 years ago · approximate date
The industrial revolution
Beginning in the late eighteenth century, engines and factories changed how people worked and travelled. Within a few generations, human activity began to alter the climate of the whole planet.
57 years ago
The first steps on the Moon
In 1969 people first set foot on the Moon and looked back at the whole Earth from its surface. The rocks they carried home still tell us how the Earth and Moon began.
33 years ago · approximate date
The world connects
The internet spread from research labs to most of the world in about thirty years. Billions of people now share one network, built well inside a single human lifetime.
the present day
Now
This is the present day. Everything you have just scrolled through happened before you were born, and almost all of it before anyone was.