Did you know that about a quarter of the Earth's geologic history is just... missing? It's not that we can't find evidence. It's that the evidence just doesn't exist. Physically. This is not a joke, or an exaggeration, or a conspiracy. It's a scientific fact that has an equally mysterious name: The Great Unconformity.

Today you will learn:

Where and why did a 14-kilometer layer of soil disappear without a trace across the planet? What is the connection between the Grand Canyon and the mountain ranges in Australia? How did the deadliest winter in the history of the planet become the cradle of vibrant life? Who turned off Earth's magnetic field 500 million years ago?

We're off to explore the mysteries of the grandest events in planetary history. The mystery of the Great Unconformity!