Chapter 032
THE BIG FREEZE - the ice reached the equator, and it happened twice
The ocean’s surface froze over. Liquid water remained beneath the ice.
An animated history of Earth
4.54 billion years, told one layer at a time.
Strata is the whole story of this planet, 88 chapters sited and counting — a new story every two days, cut entirely from paper. It starts with a cloud of dust and ends with you.
88 chapters sited12 arcsOne every two days
The latest chapter
Ice across the ocean.
Latest chapters
Newest layers first.
THE CAMBRIAN EXPLOSION - nobody agrees what switched the animals on
THE FIRST ANIMAL - seventy years to prove a smear was alive
THE GARDEN - the seafloor was crowded, and almost nothing had a face
Chapter 031
A Billion Years Are Missing From the Grand Canyon
Chapter 030
MITOCHONDRIA - the cell that got swallowed and never left
Chapter 029
THE NUCLEAR REACTOR - it ran itself on and off for 100,000 years
Coming up · not out yet
- The Garden (the Ediacaran seafloor)
- The First Animal
- The Cambrian Explosion
The dig plan
Twelve arcs, read like a core sample.
The youngest rock always sits on top — so the story is told from the bottom up. Tap a layer to see what’s buried in it.
4.57 – 4.40 billion years ago
Birth of a Planet
Accretion, Theia, and the making of the Moon.
- Tent-pole
- The Theia impact
- Span
- 4.57 – 4.40 billion years ago
A chapter from this layer: “Theia — the day Earth had a twin, and ate it”
The clock we tell time by
If Earth’s history were one year
Every chapter stamps its date on the Earth Calendar: the planet’s 4.54 billion years mapped onto a single year. January crawls. December sprints.
Jan 1
Earth forms
A cloud of dust collapses into a planet.
Feb 21
First life
Chemistry becomes biology in the early oceans.
Jun 21
The air turns to poison
The Great Oxidation Event rusts the oceans.
Nov 18
The Cambrian explosion
Eyes, armor, hunters — animals arrive.
Dec 26
The dinosaurs die
An asteroid ends a 175-million-year reign.
Dec 31, 11:59:37 PM
All recorded history
Everything ever written happens in the last 23 seconds.
A whole planet’s past. One calendar year.
Earth forms on January 1. Each day on this calendar covers about 12.4 million years. The pins below mark positions stated in the published chapters.
Some chapters pause the Clock to follow a clue. A pin can mark the age of a rock even when the event is still hard to date. Choose a month and see what turns up.
A red pin marks a chapter position. Empty months have no published pin here.
August
- August 17Chapter 029 · THE NUCLEAR REACTOR - it ran itself on and off for 100,000 years
The chapter’s chosen position within the range of published reactor ages.
- August 21Chapter 030 · MITOCHONDRIA - the cell that got swallowed and never left
The pin marks fossil evidence for complex cells, not the moment of the merger.
Meet the cast
The character cabinet
Meet the worlds that crashed and the cells that kept going. Each portrait opens a story, with clues you can find in rock or living things.
Community
Dig with us.
Watch it layer by layer
A new chapter lands every two days on YouTube, with cuts for every other platform you already live on.
Steer the dig
When a chapter strikes something you love, we stop and dig deeper — the comments literally reroute the plan.
Keep us honest
Spot an error? Say so. Corrections are credited in the next chapter’s notes.
