Think you know Mike Rowe? See for yourself by checking out his Top Ten lists. And, take a Dirty Quiz.

  Take a video tour up the mountain. And follow climber David Tait's blog as he tackles an Everest record.

  New observations by the Spitzer Space Telescope reveal that our moon, formed by a huge collision, is a rare thing.

  See how the crew works with Bear Grylls on some of his more daring exploits. Plus, put Bear back together again.

  View classic Planet Earth video highlights. And become a wildlife photographer: Play Mission: Planet Earth.