High Quality Content by WIKIPEDIA articles! The Blue Marble is a famous photograph of the Earth taken on December 7, 1972, by the crew of the Apollo 17 spacecraft at a distance of about 29,000 kilometres (18,000 mi). The name also has been applied by NASA to a modern series of image data sets covering the entire globe at relatively high resolution, created by carefully sifting through satellite captured sequences taken over time, to eliminate as much cloud cover as possible from the collated set of images. The snapshot taken by astronauts on December 7, 1972, is likely one of the most widely distributed photographic images in existence. The image is one of the few to show a fully illuminated Earth, as the astronauts had the Sun behind them when they took the image. To the astronauts, Earth had the appearance of a glass marble (hence the name).