The lead contender for the first art on the moon would have touched down in 1969 on the lunar module of the Apollo 12 mission. Dubbed the “Moon Museum,” the piece was a stamp-sized tile sporting drawings by six leading artists of the time, including Andy Warhol and Robert Rauschenberg. Although the coalition asked NASA to approve the endeavor, it didn’t receive a response.

“At the time, the concept of putting art on the moon was an avant-garde idea for the NASA administrator,” says Carolyn Russo, art curator at the National Air and Space Museum in Washington, D.C. “They tried to get official permission, and they were not able to.”

And so they went rogue. Allegedly, a NASA engineer snuck the tile onto the lunar module’s leg, beneath the brilliant gold layers of insulation, before the mission blasted off. There’s no photograph of the Moon Museum in place, however; the only way to be sure the tile made it would be to visit the lander’s outpost on the moon.