Credible source?

According to astronaut Edgar Mitchell--who has walked on the moon--aliens = a big fat YES:

"I happen to have been privileged enough to be in on the fact that we've been visited on this planet and the UFO phenomena is real," Dr Mitchell said.

"It's been well covered up by all our governments for the last 60 years or so, but slowly it's leaked out and some of us have been privileged to have been briefed on some of it.

"I've been in military and intelligence circles, who know that beneath the surface of what has been public knowledge, yes - we have been visited. Reading the papers recently, it's been happening quite a bit."

My first guess is hoax (this did occur on a radio show, after all); my second guess is this guy is craaaaazy/confused/paranoid; my third guess is that, holy shit, aliens dude. But the probability span of those guesses is 90%, 9.99999%, 0.11111%, respectively.

EDIT: Correction: that should be 90%, 9.99999%, 0.00001%.