Earth Before Humans

Snowball Earth: When Ice Reached the Tropics

Imagine sea ice near the equator, glaciers grinding across continents, and sunlight reflected back into space by a planet turning white. During the Cryogenian Period, Ear

Pangaea: How a Supercontinent Assembled and Broke Apart

Pangaea did not appear when continents slid together like tidy puzzle pieces, and it did not break when one crack split the planet. It was assembled through a long sequen

The Great Dying: Earth's Largest Mass Extinction

About two hundred fifty-two million years ago, ecosystems collapsed in oceans and on land with a severity unmatched by any later mass extinction. The event is called the

The Ediacaran Seafloor: Life Before Familiar Animals

Before shells, claws, and recognizable fish, ancient seafloors carried quilted bodies, branching fronds, disks, and tracks made by creatures that rarely resemble modern a

The First Forests: When Roots Remade the Land

A forest seems like scenery until it does not exist. Before trees, riverbanks lacked deep root networks, soils were thinner, and tall canopies did not divide sunlight int

Chicxulub: The Impact That Changed Life on Earth

Sixty-six million years ago, an asteroid struck near the Yucatan and altered the course of life. Follow the evidence linking Chicxulub to the K-Pg extinction, the rapid c

Burgess Shale: A Lost Ocean Preserved in Stone

High in the Canadian Rockies, stone preserves an ocean community about 508 million years old. Explore how the Burgess Shale captured soft-bodied animals, what Charles Doo

The Great Oxidation: When Microbes Changed the Sky

For much of early Earth, the atmosphere contained almost no free oxygen. Follow the evidence for the Great Oxidation Event, when microbial photosynthesis and a changing b