Chicago isn't known as a hotbed of UFO activity, but O'Hare Airport is the home of one of the most publicized sightings of the last decade. A flying saucer-like object" was spotted over Concourse C of the United terminal in November 2006 by pilots, airline management and mechanics. The incident, reported by a Chicago Tribune columnist a few weeks later, noted the object was first seen by a United ramp worker around 4:30 p.m.. After that, a variety of witnesses said the object was dark gray and 6 to 24 feet in diameter. The object was silent and appeared just below the 1,900-foot cloud deck, until shooting off into the clouds and leaving a circular hole shape in the clouds. The Federal Aviation Administration ... dismissed the incident as a weather phenomena. But for Center for UFO Studies Scientific Director Mark Rodeghier, the possible alien craft that appeared in the center's own proverbial backyard remains a mystery worth exploring. "It's an unknown object over O'Hare, and it's seen by official personnel, and does United or the FAA take it seriously? Of course not, they have zero interest because UFOs can't exist. But how can you not worry about something hovering over an airport after 9/11? It doesn't make sense," Rodeghier said. Journalist Leslie Kean also wrote about it in her book "UFOs: Generals, Pilots and Government Officials Go On The Record" and talked about in on "The Colbert Report" with Stephen Colbert in 2010, saying the government should investigate the O'Hare incident.