Why Did The Earth Totally Freeze For 100 Million Years?
56:39
What Was The Earth Like 500 Million Years Ago?
27:02
What Was Earth Like 3 Billion Years Ago?
37:54
What's Hidden Under the Ice of Antarctica?
36:10
What Was The "Boring Billion" Really Like?
30:49
What is the Oldest Fossil on Earth?
31:31
Where Did Earth's Water Come From?
1:51:36
What Will Humanity Do If We Ever Discover Aliens?
2:03:29