On December 21, 1968, three humans climbed atop a massive rocket and left our planet for a six-day round-trip journey to our nearest companion in the solar system, the Moon. During the Apollo 8 mission, NASA astronauts Frank Borman, James Lovell, and William Anders flew hundreds of thousands of miles across translunar space, becoming the first human beings to see the entirety of the Earth at once with their own eyes. They orbited the Moon 10 times, and came within 70 miles of the surface, taking dozens of photographs, including one of the most famous and powerful images in human history, Earthrise, a compelling view of our home world, vibrant and colorful, contrasted against the forbidding blackness of space and the challenging landscape of the Moon. Fifty years ago, Apollo 8 set the stage for Apollo 11, when men would first set foot on the Moon, seven months later.