When re-entering the United States, it's necessary for every traveler to go through U.S. customs first. And it doesn't matter who you are or where you're coming from – even if you came from the Moon. That's what the three members of the Apollo 11 crew found out when NASA declared its moon rock and moon dust samples it brought back to Earth.
The Apollo 11 customs declaration.
The idea of going through customs makes one think of carrying luggage through a conveyor, meeting with an immigration official who stares at your passport and asks you where you went on your travels. That, of course, is not what happened to Neil Armstrong, Buzz Aldrin, or even Michael Collins after they safely splashed down in the Pacific Ocean. They were too busy being hailed as heroes for living in space for eight days, spending 21 hours on the Moon, and then coming home.
Besides, if you look at their customs declaration, it appears there's no airport code for "Sea of Tranquility" or "Kennedy Space Center." And "Saturn V Rocket" is definitely not on the list of possible aircraft you can take from anywhere to anywhere – unless you're Neil Armstrong, Buzz Aldrin, or Michael Collins.
Don't forget to sign for your cargo, you bums.
The funny part about the Apollo 11 customs declaration is that the form lists the departure area as simply "moon."
In all likelihood, this is a pencil-whipped form, done because it's supposed to be done and because United States airspace ends after a dozen or so miles above the Earth's surface, and the Apollo team definitely went 238,900 miles away.