It was the first photograph taken of the whole round Earth and the only one ever snapped by a human being. You can’t see the Earth as a globe unless you get at least twenty thousand miles away from it, and only 24 humans ever went that far into outer space. They were the three-man crews of the nine Apollo missions that traveled to the moon between 1968 and 1972, six of which landed there successfully (three men went twice). But only the last three saw a full Earth.

…

(The true camera image is upside-down by earthly standards, showing the South Pole at the top of the globe, because the camera was held by a weightless man who didn’t know down from up. Most reproductions invert it to align with our expectations.)

Most people who glanced out the window and saw something like that would be distracted no matter how busy they were. That’s what happened on Apollo 17 when the spacecraft was some 28,000 miles from Earth and crossing the path between it and the sun. All three men aboard had mission-critical tasks to perform at the time, tasks they had simulated hundreds of times on the ground. Tasks they could almost do automatically. And they weren’t immune to astonishment.

After the picture became famous all three remembered seeing that remarkable sight and each was pretty sure they had snapped the shot. NASA policy is to credit the entire crew for all mission photography, so there is no official position. Ron Evans died in 1990 without relinquishing his claim, and forty years later there is still a running argument between Cernan and Schmitt about who took the Blue Marble Shot. Those four decades have shown it to be the most significant thing they brought back from their expedition, far more meaningful than the moon rocks they gathered, so it matters to them. A lot.

From The Blue Marble Shot: Our First Complete Photograph of Earth – Al Reinert – Technology – The Atlantic

Read more