2
What Was Earth Like 4 Billion Years Ago?
3
The Mystery of the Late Heavy Bombardment
4
Where Did Earth's Water Come From?
6
What Was The Last Common Ancestor of all Life on Earth?
7
Were Volcanoes The Key To Life?
8
Did Life on Earth Come From Space?
9
What Would The Earth Have Been Like Without Life?
10
What is the Oldest Fossil on Earth?
11
How The Earth Got Its Magnetic Field (And Why It Might Not Protect Us Much Longer)
12
What Was Earth Like 3 Billion Years Ago?
13
How Bad Was The Great Oxidation Event?
14
How Did Life Recover From The First Mass Extinction?
15
What Would The Earth Be Like Without Photosynthesis?
16
What Was The First Virus?
17
What Is The Other 99.99% Of Life?
18
What Was The Earth Like 2 Billion Years Ago?
19
A Tour of Earth's Ancient Supercontinents
20
A Tour of Earth's Ancient Superoceans
21
What Was The "Boring Billion" Really Like?
22
What Was The First Complex Life on Earth?
23
What Was The Earth Like 1 Billion Years Ago?
24
What Was The First Fungus?
25
Why Did The Earth Totally Freeze For 100 Million Years?
26
Were These The First Animals?
27
How Far Back In Time Could You Have Survived On Earth?
