The Apollo 8 mission's impressive list of firsts includes: the first humans to journey to the Earth's Moon, the first manned flight using the Saturn V, and the first to photograph the Earth from deep space.
As the Apollo 8 command module rounded the farside of the Moon, the crew could look toward the lunar horizon and see the Earth appear to rise, due to their spacecraft's orbital motion.
The famous picture that resulted, of a distant blue Earth above the Moon's limb, was a marvelous gift to the world.