Dig Quest: Earth’s Story
Uncover each layer to travel from 4.54 billion years ago to the last Ice Age. Every fact is cited.
Tap a layer to dig in. Start at the very beginning and dig toward today.
0 of 8 layers uncovered
Dust and gas around the young Sun clumped into rocks, the rocks collided and merged, and Earth grew. Scientists date Earth to 4.54 billion years (less than 1% uncertainty) using lead isotopes and meteorites.
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A Mars-size body called Theia likely struck young Earth. The debris formed the Moon. Apollo rocks show the Moon formed about 60 million years after the solar system began and was once covered by a magma ocean.
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A tiny zircon crystal from the Jack Hills of Western Australia is 4.404 billion years old — the oldest known piece of Earth. Its chemistry points to continental crust and liquid water very early on.
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Tiny ocean microbes, likely ancestors of cyanobacteria, made oxygen by photosynthesis. Around 2.4 billion years ago oxygen built up in the air — the Great Oxidation Event — paving the way for complex life.
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The Burgess Shale in the Canadian Rockies preserves soft-bodied sea animals from the Cambrian, 508 million years ago, recording the rapid diversification of life called the “Cambrian Explosion.” Charles Walcott collected some 65,000 specimens there for the Smithsonian.
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The end-Permian extinction was the largest in Earth’s history: about 96% of species were lost. Massive volcanic eruptions in Siberia released carbon dioxide, linked to warming and ocean acidification. Life took millions of years to recover — but it did.
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An asteroid 10–20 km wide struck near today’s Yucatán, forming the Chicxulub crater. About 76% of species died out, including all dinosaurs except birds. Mammals then flourished.
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At the Last Glacial Maximum, about 20,000 years ago, ice sheets covered Canada and northern Europe and sea level was about 120 meters lower. Ice cores from Greenland and Antarctica record this climate history year by year.
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