On December 24, 1968 at about 4:38 pm—just before we took one giant leap—Apollo 8 orbited the moon snapping photos and taking reconnaissance. The small capsule held astronauts Frank Borman, Jim Lovell, and William Anders.

As they orbited, they made a significant turn which brought into view the earth rising over the moon. They snapped a picture that would appear on the front cover of TIME and become an icon of the environmental movement. It was listed in LIFE magazine’s 100 photos that changed the world.

According to Business Insider, William Anders described the event in a television interview:

I don’t know who said it, maybe all of us said, ‘Oh my God. Look at that!’ and up came the Earth. We had had no discussion on the ground, no briefing, no instructions on what to do. I jokingly said, ‘well it’s not on the flight plan,’ and the other two guys were yelling at me to give them cameras. I had the only color camera with a long lens. So I floated a black and white over to Borman. I can’t remember what Lovell got. There were all yelling for cameras, and we started snapping away.

To commemorate the 45th anniversary of the event, NASA’s Goddard Space Flight Center created a video showing the events surrounding the historic photo. They released the video on December 20th of last year.

The video combines the photos of the moon being taken at the time, the records of the flight and the photos taken of the moon to create a simulation showing the sequence of events.