The Blue Marble
The Blue Marble is a photograph of the Earth. It was made on December 2, 1972, by the crew of the Apollo 17 spacecraft. At that time they were on their way to the Moon at a distance of about 18,000 miles (29,000 km) from the Earth. It is one of the most reproduced images in human history.
- Petsko, Gregory A (2011). "The blue marble". Genome Biology 12 (4): 112. doi:10.1186/gb-2011-12-4-112. http://www.springerlink.com/content/f61183q243148q3w/.