It's an age-old question: Are we alone in the universe?

As the documentary Out of the Blue rightly points out, brilliant and reputable scientists believe that the conditions for intelligent life exist on thousands of planets. But then there's that other question that separates the scientists from the believers, the witnesses from the skeptics if aliens are out there, have they come to visit?

James Fox, the producer of Out of the Blue, says that aliens are out there. "They're flying around. They're here and they've been here."

He also believes that they have incredible technical ability, saying that they can "fly rings around our fastest jets. Yes. That's what I've been told. They can literally almost disappear in place."

Out of the Blue is an attempt to weed out the wackos and present credible witnesses who say they saw what looked like alien spacecraft. Witnesses like former President Carter, who said, "I saw one, but I don't know where. It just disappeared." And Mercury astronaut Gordon Cooper, who says he saw "this typical saucer shape, double-cylindrical shape, metallic."

Flying Saucers

"I looked up and all of a sudden there was this, you know, I got to say it, flying saucer," said Sean Thackery, from Marin, California, one of the eyewitnesses in the film.

"You've got this phenomenon taking place that's never been properly explained," said Fox. "You know, people - people wanna know."

The subject of UFOs is one of those things that never gets a satisfactory answer, and never quite seems to go away. Now, 60 years after the reported crash of a UFO in Roswell, New Mexico, and with the French government releasing its UFO archives, there are new efforts to prove alien spacecrafts really exist.

The documentary begins with an odd, but in a way undeniable, incident that occurred in Phoenix in March 1997, known as the "Phoenix Lights."

Hundreds and possibly thousands of people, many of them looking at the Hale-Bopp comet, reported seeing an array of lights and an enormous delta-shaped craft. The first report of a strange flying object came about 8:20 p.m. from a former police officer in Paulden, Arizona. Over the next 40 minutes, people gave similar reports of an object along a 20-mile route south to Phoenix and Tempe.

"It's coming across the sky," said witness Tim Ley of Phoenix, "and as it's moving, it's blocking and unblocking the stars. There was actually a shape."

"It passed right in front of us. It was just about right above eye length," said Mike Fortson. "My estimate of the size of the craft from the nose as it passed us where we lived to the end of the left wing that passed in front of us was over 5,000 foot long."

There was such an uproar about what people described seeing that ABC News did a story about it back in 1997. At the time, then Arizona Gov. Fife Symington called a news conference, spoofing the whole thing by bringing an "alien" into the room.

'I Know What I Saw'

What Symington did not say then was that he also had seen the object over Phoenix. But in Out of the Blue, he says that "we all experienced a very exciting sighting of some kind of a craft of unknown origin. Nobody's ever been able to explain it. Most of us feel that it was definitely, you know, of alien origin. Enormous. Inexplicable."

Symington is an Air Force veteran, and a pilot. When asked whether he was worried about speaking out, he said, "I know what I saw and what I believe and I'm not afraid to say it publicly. I'm, I'm really not concerned about somebody's opinion about that, frankly."

Among other claims, Fox focuses on a 1980 report of UFO sightings at an American air force base in England - the so-called "Bentwaters" incident. Three former Air Force security officers told Fox about actually touching a small, strange craft that landed outside the base.

"There's no doubt about it, there's some type of strange, flashing red lighting ahead," said Lt. Colonel Halt in the documentary. "The closer we got, the more the white light dissipated, but what appeared was a triangular craft. When we approached it, it was, I'd say it measured probably about nine feet long, maybe six feet high."

Sgt. Jim Penniston made drawings of what appeared to be symbolic drawings that, he said, were on the skin of the craft.

'That's Not How Science Works'

But when it comes to UFOs, there are plenty of skeptics. One man who makes his living as a professional skeptic is, well, skeptical.

Michael Shermer, the editor of Skeptic Magazine, says, "The parade of astronauts or police officers or politicians like Jimmy Carter - it's irrelevant. Because they're human and they're brains and nervous systems and sensory apparatus are structured just like the average Joes."

Shermer spends a lot of time with reports of UFOs and space aliens, and has this to say about the documentary: "Um, the facts are true. The, uh, the story is well told and well produced. But that's not how science works. In science we have to have some way of testing to get an answer. It's this or this. And we have to have some way of weighing the evidence. And short of an actual experiment to run you have to have debate."

UFO sightings, even the most interesting ones, tend to share similar characteristics. There are no pictures, or the pictures are blurry. Or maybe there are pictures, but they disappeared into government archives never to be seen again.

That's what the late astronaut Gordon Cooper said, but the documentary says that, "Not every government chooses to deny the existence of UFOs. Since the fall of communism in 1989, information surrounding the subject has become much more accessible in Russia."

Cosmonaut Pavel Popovich was one of Russia's earliest cosmonauts. He joins the ranks of an increasing number of military personnel who have testified as to the validity of the UFO phenomena.

A Leap of Explanation

The documentary ends by saying that, "The discovery that we are being visited by extraterrestrials would be one of the greatest in human history. Such a discovery would profoundly alter the perception of ourselves and our place in the universe."

But Shermer remains unconvinced. "You can't discount the fact, unfortunately, that people lie or they misperceive and then tell the story incorrectly or exaggerate. Everybody knows about the human foibles of deception and self-deception and exaggeration. We all do it. So unfortunately we can't just, we can't always count [on] eyewitness accounts being reliable."

Shermer says the problem comes in a kind of leap of faith - with UFOs it's a leap of explanation.

"In science it's OK to just say, 'Let's just withhold judgment for now and do more research. We don't have to commit to some big, grand theory of aliens visiting us. Let's just say we don't know what it is. But we have to follow the standards of evidence in science that we apply everywhere else. In no other science would anybody accept just a few random anecdotal stories and grainy videos and blurry photographs."

"The question itself I think is legitimate," he said. "It's interesting, it's fascinating. It's mythic in scale one of the grand questions. It's like the God question or, you know, the meaning-of-life question. It's one of those, on that scale. So you'd have to be made of wood not to be interested and, you know, have they come here? Are they up there?"