That televised cockroach gag was small potatoes compared to another Apollo 12 prank. Conrad's crewmates on this venture were module pilots Alan Bean and Richard F. Gordon Jr. Once they reached the moon, these astronauts had a long itinerary ahead of them. Part of their mission was to remove components from the Surveyor 3 probe, which landed in a crater back in 1967. Other objectives ranged from surveying the terrain to taking snapshots of sites that future crews might explore. All these tasks had to be completed in a specific order — and within some rigid time constraints.
To help the men stay on top of things, NASA tied spiral-bound wrist notebooks to the arms of their spacesuits. The notebooks had detailed instructions printed inside, along with a scientific glossary.
Something else was in there, too. On Nov. 19, Gordon was orbiting above the moon while Bean and Conrad busied themselves down on the surface. They were amused to discover little cartoons scrawled inside the wrist notebooks. And then, with a fateful page-flip, Bean suddenly found himself looking at the last thing he'd ever expect to see in outer space: a "Playboy" centerfold.
Unbeknownst to him, the Apollo 12 backup crew had printed a copy of Miss December 1969's topless glamour shot into his wrist notebook. Beneath it, the caption read "Don't forget — describe the protuberances." And she wasn't alone. Bean's wrist book also featured Miss January 1969, too. Meanwhile, Conrad got two centerfold photos of his own.
Conrad and Bean were careful to avoid saying anything about the prank out loud, however. That's because built-in spacesuit microphones were radioing their comments back to Earth. As Bean points out in hindsight, the humor probably would've been lost on America's taxpayers.