BBC Earth is celebrating 50 years of Earth Day with Earth Week, a special line-up of programming which looks at the beauty of our planet both up close and from far away, screening each evening at 8.30pm from Monday, April 20.  The channel will premiere Blue Planet Revisited which returns to two key locations from Blue Planet II to explore the particular challenges facing the marine eco-system and wildlife in Australia’s Great Barrier Reef and the Bahamas. In Earth From Space cameras hundreds of kilometres up in the sky capture natural spectacles on an epic scale showing us its extraordinary beauty and diversity in astonishing detail. The week will finish with a special Sunday screening of every episode of David Attenborough’s iconic Planet Earth II.