The first humans to circle the moon were the Apollo 8 astronauts.
The "Earthrise" photo that showed Earth rising above the lunar landscape was one of the highlights of the mission.
Our blue marble had never been seen before by a human.
The most influential environmental photograph ever taken was described in Life Magazine's " 100 Photographs That Changed the World" by renowned wilderness photographer Galen Rowell.
The image of our planet in the blackness of space made people more aware of its vulnerability.
One of the most reproduced space photos of all time is "Earthrise", which appeared on US postage stamps, posters, and the cover of Time magazine in 1969. Since Apollo 8 was sent to study the moon's surface, many have pointed out the irony of the photo.
Robert Zimmerman wrote in his book " Genesis: The Story of Apollo 8: the First Manned Flight to Another World" that no one had thought of photographing the Earth from the moon.
The famous photo was taken during the mission's fourth pass around the moon, when it was possible to see the earth above the lunar horizon.
The astronauts weren't prepared for the moment, including the pilot of the lunar module.
"I don't know who said it, maybe all of us said, 'Oh my God,'" he said in the 2012 interview. The Earth came up and said, 'Look at that! We didn't have any instructions on what to do. I joked that it wasn't on the flight plan and the other two guys were yelling at me to give them cameras. There was only one color camera with a long lens. I took a black and white picture. I don't know what he got. We snapped away because there were all yelling for cameras.
Both Borman and Anders claimed to have taken the picture. Borman, who was the first to recognize the significance of the moment, took a black-and-white photo before the photographer took the famous picture.
The Elusive Apollo 8 Earthrise Photo was written by Fred Spier, a senior lecturer at the University of Amsterdam.
Frank Borman was the first to the importance of the picture, followed by James Lovell. William was in charge of taking the pictures. In order to do so, he had to follow a tight and well-defined photo plan, in which there wasn't much room for impromptu snapshots.
"Anders first offered some resistance and then did what the other told him to do," Spier said. The picture came as a result of the combined efforts of all three astronauts and it now seems beyond doubt.