OUT OF THE BLUE

Blue Planet, 8pm, BBC1

WITH its crushing pressure and total darkness, the deep ocean couldn’t be a more hostile environment. For us humans, that is. For this second episode, the cameras go five miles below the surface where once we thought life was impossible. The remarkable footage reveals the hardy and extraordinary creatures that live there (including the intriguingly named flapjack octopus) before going even further down to the Mariana Trench, the deepest place on Earth, where only three humans have ever been.