^ apparently it was a bit of a joke.
http://www.openculture.com/2013/12/sign-immigration-form-after-the-first-moon-landing.html
Quote:The form, NASA spokesperson John Yembrick told Space.com, is authentic. And, he says, it was a joke. He does not, however, say exactly when the form was signed, either on the day the crew splashed down or sometime afterward. They did not actually arrive in Honolulu until the 26th. After their return,
http://www.openculture.com/2013/12/sign-immigration-form-after-the-first-moon-landing.html