 One of the most famous aspects of the flight was the Earthrise picture that was taken as they came around for their fourth orbit of the Moon . This was the first time that humans had taken such a picture whilst actually behind the camera , and it has been credited with a role in inspiring the first Earth Day in 1970 . It was selected as the first of Life magazine 's 100 Photographs That Changed the World . Apollo 11 astronaut Michael Collins said , " Eight 's momentous historic significance was foremost " ; while many space historians , such as Robert K. Poole , see Apollo 8 as the most historically significant of all the Apollo missions . 
