7-th episode of 37-th season "Horizon"

What "Horizon" 7-th episode about

There is a controversial theory that for millions of years the Earth was entirely smothered in ice, up to one kilometer thick. The temperature hovers around -40?C everywhere, even in the tropics and the equator. If it did, then virtually nothing could survive this ferocious climate. There are some tantalizing geological clues that show this theory may be true but the problem is, the clues and the Snowball Earth theory defy the laws of nature.

Episode number: 7

Episode name: "Snowball Earth"

Episode release date: 22 february 2001 at 21:00

Status: aired