4 – Autumn

Original air date: 16 November 2011

A graphical presentation of what happens in the episode

A more detailed timeline can be seen below

More episodes

1 - To the Ends of the Earth
2 - Spring
3 - Summer
5 - Winter
6 - The Last Frontier
7 - On Thin Ice
8 - Science at the end of the earth
9 - The Epic Journey
Series in retrospect