At 12:51 PM Eastern, a Saturn V rocket lifted Frank Borman, Jim Lovell, and William Anders from Kennedy Space Center on the first crewed mission to leave low Earth orbit entirely. Three days later they would orbit the Moon ten times, and Anders would photograph 'Earthrise,' one of the most reproduced images in history, reframing how humanity saw its own planet.
NASA moved Apollo 8 up the schedule in a gamble born of Cold War anxiety: intelligence suggested the Soviets might attempt a crewed lunar flyby first, and the lunar module wasn't ready for the mission originally planned. So engineers rewrote the flight plan to send a crew all the way to the Moon on only the third-ever flight of the massive, still-unproven Saturn V.
The launch itself was violent — commander Frank Borman later said the ride felt like being in a train wreck. Once free of Earth's gravity well, the crew became the first humans ever to leave low Earth orbit, and over the following days they watched their home planet shrink to a marble hanging in blackness.
On Christmas Eve, orbiting the Moon, the astronauts read from the Book of Genesis in a broadcast watched by hundreds of millions, one of the most-watched television events of the era. Anders's photograph of Earth rising over the lunar horizon, taken almost as an afterthought, became a touchstone image of the environmental movement, a reminder of the fragile blue world they had left behind.