How the Earth may have looked from space 600 million years ago, frozen in snow and ice

Snowball Earth

Snowball Earth describes a theory that for millions of years the Earth was entirely smothered in ice, stretching from the poles to the tropics. This freezing happened over 650 million years ago in the Pre-Cambrian, though it's now thought that there may have been more than one of these global glaciations. They varied in duration and extent but during a full-on snowball event, life could only cling on in ice-free refuges, or where sunlight managed to penetrate through the ice to allow photosynthesis.

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Time period when this happened

Cryogenian period Cryogenian period
A succession of incredibly harsh ice ages waxed and waned during the Cryogenian. It is nicknamed Snowball Earth as it's been suggested that the glaciation was so severe it may even have reached the equator.

Ancient Earth habitats

BBC News about Snowball Earth

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