Sir David Attenborough narrates this critically acclaimed series that dives deep into the marine environment of Planet Earth. Although two-thirds of the world's surface is covered with water, scientists know less about the oceans than they do about the surface of the moon. This limited series travels from various coasts to the poles to examine watery denizens ranging from the gigantic blue whale to microscopic coral polyps.

A look at the passage of time through the changing seasons, human evolution and everyday life.

A heroic expedition braves snow-whipped precipices and discovers the dreaded humanoids. But wait – these are extraterrestrial yetis who zipped in from outer space to conquer Earth by melting the polar ice caps with high-energy proton fields. Will mankind be global-warmed into surrender?