DAVID GREENE, HOST:
A few weeks ago, Matty Roberts posted an online call-out to form a hunting party to find extraterrestrials in the Nevada desert. He did not think people would take him seriously.
MATTY ROBERTS: When I posted the original event, I wasn't intending anything to actually happen. It was a meme that I was going to post on a meme page because I thought it was funny, kind of cheeky. It was like tongue-in-cheek - almost serious, but not really. And then it just completely took off, so now I'm in kind of damage control mode.
RACHEL MARTIN, HOST:
His online joke has turned into a real-life call to action. It's now become a massive gathering in search of the paranormal. And it's actually scheduled for September 20. More than 2 million people say they're going to go. The Air Force is warning them not to do it, but the county sheriff is still preparing for it, all because Roberts created this Facebook event.
ROBERTS: It's Storm Area 51. They can't stop all of us.
GREENE: Yes, that Area 51, as in the top-secret U.S. military base that has long inspired alien conspiracy theories. Here's how Roberts laid out his plan on Facebook.
ROBERTS: We will all meet up in rural Nevada and coordinate our parties. If we Naruto run, we can move faster than their bullets. Let's see them aliens.
MARTIN: Air Force officials are discouraging would-be raiders from showing up at all in Area 51, and they may have nowhere to stay if they show up anyway. Local hotels are running out of rooms. The town of Rachel, Nev. has a population of only 54. Even a thousand visitors would overwhelm emergency services. So Roberts is now backpedaling.
ROBERTS: I'm really trying to direct people away from actually going towards the military base because that both is dangerous, and it's a national security threat. And I don't really want anybody out there getting hurt or really presenting a threat to the American government, you know? So I'm trying to direct people towards the safer option of just going to one of these mini parties that's being set up.
GREENE: Though outsiders partying in small-town Nevada, that may be a different kind of alien invasion. Transcript provided by NPR, Copyright NPR.