What was the mysterious object seen over Chicago International Airport in 2006?

It all began at 4:30 PM on Tuesday, November 7, 2006.  Twelve airport employees reported to federal authorities that they were watching a metallic, saucer-shaped object over gate C-17.  Suddenly, the UFO took off, straight up through overcast skies.  It left behind an open hole of clear air in the cloud layer. 

Later, the Federal Aviation Authority (FAA) stated that weather phenomenon caused the sighting and that the agency would not be investigating the incident.  The media gave the event huge coverage, which is unusual for the major news outfits.  Television news networks, when they do cover UFO reports, usually do so in a mocking style that was absent here. 

There appeared to be a cover-up After reporting the sighting, the witnesses were told by their supervisors not to talk about it, or they would be fired.  However, some of the witnesses are talking about it, albeit with anonymity.  Recently, they have indicated that the UFO may have effected the airports air traffic.  And, of course, there is the internet.

The testimony of several witnesses was corroborated by a photograph that was posted on the internet.  One witness confirmed that the photo is what she saw.  Another said that the object was solid and not a lenticular cloud.  A lenticular cloud is saucer-shaped and some debunkers claim that such clouds are mistaken for spacecraft.

However, controversy swirls around the authenticity of this photo.  Now, there is another photo  in the public domain that may be more valid.