Earth Day is April 22, and to commemorate the occasion, you can currently save on a variety of documentaries from the BBC’s Planet Earth collection in 4K UHD format at Amazon. Even if you’ve already seen some of these films, streaming service resolution can’t compare to the visuals on a physical disc. While this isn’t a comprehensive collection of nature documentaries produced by the BBC, it is an excellent opportunity to explore the majesty of our little blue marble without leaving the safety of your living room.