The U.S. military was on the lookout for space aliens as recently as 2007-12. That may seem like something out of a science fiction novel or film, but it's confirmed by a front-page New York Times article about a little-known Defense Department program that sought evidence of aerial visitors from beyond our planet. It didn't prove any existed, but couldn't explain a November 2004 sighting of strange aircraft that flew in seemingly impossible ways.

For two weeks that fall, a Navy cruiser off San Diego, Calif., tracked mysterious objects that appeared suddenly, hovered and then climbed swiftly or vanished. Two Navy fighter pilots tried to investigate an oval craft, but it "accelerated like nothing I've ever seen," retired Commander David Fravor told The Times. He was "pretty weirded out," the former pilot acknowledges. "I have no idea what I saw. It has no plumes, wings or rotors and outran our F-18s." The military released a fuzzy, infrared video of the night encounter (see it below). Experts caution against assuming it was a spacecraft. Just because an object is unidentified doesn't mean it came from another galaxy or universe, says noted astrophysicist Neil deGrasse Tyson. Some close encounters may involve weather-related electric fields or secret military prototypes that regular pilots don't know about.

The newly disclosed inquiry by a small team was called the Advanced Aerospace Threat Identification Program. "The program produced documents that describe sightings of aircraft that seemed to move at very high velocities with no visible signs of propulsion, or that hovered with no apparent means of lift," says the recent full-page article by three Times reporters. The government project paid private contractors to analyze military sightings of mysterious airborne objects. "There are still those observations that defy explanation," says Luis Elizondo, former head of the Pentagon effort. At a site called space.com, columnist Leonard David posts: "It all has the feel of sliding open a top drawer in a new 'X-Files' TV episode."

UFO believer says: "Personally, I don't need verification from the government. But for the mass public, it's important to know that there is advanced technology in our skies." – Jan Harden, director of the Mutual UFO Network

Scientist says: "Call me when you have a dinner invite from an alien." -- Neil deGrasse Tyson, New York City planetarium director and author

Overseas expert says: "Extraterrestrial visitation might be unlikely, but if a single case turned out to be true, it would be a game-changer." – Nick Pope, who ran a British military UFO investigation in the early 1990s