File Photo: The Crew Of Apollo 17 Took This Photograph Of Earth In December 1972 While The Spacecraft Was Traveling Between The Earth And The Moon. The Orange-Red Deserts Of Africa And Saudi Arabia Stand In Stark Contrast To The Deep Blue Of The Oceans And The White Of Both Clouds And Snow-Covered Antarctica. (Photo By Nasa/Getty Images)

Happy Earth Day! Every April 22nd the world comes together to demonstrate support for environmental protection. How much do you know about Earth Day? Take our quiz below to find out.