What picture from this mission was not supposed to be public?

Skylab 4, launched on November 16, 1973, was NASA’s final journey for its first space station. Onboard, astronauts Gerald Carr, Edward Gibson, and William Pogue busily documented Earth’s stunning vistas. Among their shots: a certain controversial location.

Cue the CIA flipping out. Despite strict instructions to avoid this “super-duper secret spot”—the image was captured.

The CIA tried to classify the image retroactively, spurring a bureaucratic tug-of-war with NASA and the State Department. The intel guys argued about the crucial need for secrecy, given that not even their photo interpreters had clearance for such images.

In the end, the photo quietly landed in NASA’s archive, right alongside all other Skylab images—out in the open for all to see.

So here it is. Can you see what the “super-duper secret spot” was? Yup, that is Groom Lake in Nevada, AKA Area 51.