What Was The Last Common Ancestor of all Life on Earth?
Season 1 • Episode 6
How The Earth Got Its Magnetic Field (And Why It Might Not Protect Us Much Longer)
Season 1 • Episode 11
How Did Life Recover From The First Mass Extinction?
Season 1 • Episode 14
What Would The Earth Be Like Without Photosynthesis?
Season 1 • Episode 15
Why Did The Earth Totally Freeze For 100 Million Years?
Season 1 • Episode 25