NASA's nine-year-old New Horizons mission made history on Tuesday by giving Earth its first close glimpse at the on-again, off-again ninth planet, Pluto. In response, President Barack Obama tweeted:

But was New Horizons really Pluto’s first visitor? John Podesta, who left his White House senior adviser position earlier this year to run Hillary Clinton’s presidential campaign, questioned the assumption:

Podesta is a well-documented science fiction enthusiast who's regularly riffed on the X-Files tagline, “The truth is out there.”

In 2002, Podesta told reporters at the National Press Club that the U.S. government should “declassify records that are more than 25 years old.” He was, of course, discussing UFOs. “It’s time to find out what the truth really is that’s out there,” he said. “We ought to do it, really, because it’s right. We ought to do it, quite frankly, because the American people can handle the truth. And we ought to do it because it’s the law.”

Podesta also wrote the foreward for Leslie Kean’s 2010 book, UFOs: Generals, Pilots, And Government Officials Go On The Record. In it, Podesta made the same case for disclosure. “It’s time to find out what the truth really is that’s out there. The American people—and people around the world—want to know, and they can handle the truth.” 

Leaving his White House post in February, Podesta again fueled Area 51 and Roswell conspiracy theories by tweeting that his "biggest failure of 2014" was "not securing the #disclosure of the UFO files."

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Thanks to Podesta's enthusiasm, Bill Clinton's presidential library has been inundated with Freedom of Information Act requests regarding aliens in Podesta’s files. One request illustrates the general thrust of such inquiries: “2006-0492-F: All files on UFOs, Roswell, New Mexico, flying saucers, Area 51 or the TV show X-Files in the files of John Podesta."

It's somewhat surprising that they didn't seek to probe whether Podesta himself is an alien life form. And yet such requests aren't completely in the tin-foil-hat realm of conspiracy nuts. Podesta would have had access to classified documents as White House chief of staff for Clinton, since he had the highest clearance in government.

Space exploration has featured in presidential elections before. As New York magazine summarized earlier this year: Newt Gingrich promised to build a base on a moon if elected. Democratic presidential candidate Dennis Kucinich dropped a bomb in a 2008 debate that he thought he saw a UFO once. In 1992, presidential candidate Ross Perot blamed extraterrestrial life for political gridlock. "It's not the Republicans' fault, of course, and it's not the Democrats' fault," he said in a debate. "Somewhere out there there's an extraterrestrial that's doing this to us, I guess."

Bill Clinton is open to the idea of extraterrestrial life, as well. He appeared on Jimmy Kimmel’s show in 2014 and suggested that he believes we may not be alone (though he also assured us “there are no aliens” kept from us). "We know now we live in an ever expanding universe," he said. "We know there are billions of stars and planets literally out there, and the universe is getting bigger. We know from our fancy telescopes that just in the last two years more than 20 planets have been identified outside our solar system that seem to be far enough away from their suns—and dense enough—that they might be able to support some form of life."

So there’s reason to think an alien sighting might return again to presidential politics. Ted Cruz, for instance, is in charge of the Senate committee on NASA, and has even joked about aliens. “I’ll work with Martians. If—and the if is critical—they’re willing to cut spending and reduce the debt.”

As the New Horizons spacecraft flew by Pluto and beamed its first images back to Earth this week, Clinton joined in the celebrations. "Let's always keep exploring," she tweeted.

As for the existence of aliens, however, Clinton hasn’t taken a position on them. Her campaign declined to comment on the possibility of life in outer space. But UFO believers hope she may be open to the possibility of other intelligent life. Stephen Bassett, who heads the Extraterrestrial Phenomena Political Action Committee, told Roll Call in February, “As far as I’m concerned … Hillary Clinton is not going to become the president of the United States without going through the extraterrestrial issue." 

This article has been updated.