It's taken over two weeks for the Air Force to suggest that a UFO reported over Massachusetts may have only been a huge cargo plane, but even they're not sure.

Back on Jan. 8, residents of Amherst and Pelham reported a low-flying unidentified triangular or diamond-shaped object moving slowly and silently between 5:45 p.m. and 6:30 p.m., according to the Daily Hampshire Gazette. (sign up to see story)

"The only aircraft that was operating in the area was a military aircraft doing practice approaches to Westover (Air Reserve Base)," FAA spokesman James Peters told the Gazette.

Bradley International Airport, in Windsor Locks, Conn., is responsible for radar reports covering western Massachusetts, and they informed the newspaper that there was nothing unusual in the sky above the Amherst-Pelham area during the time period when the UFO was seen.

The Associated Press reports that a Westover spokesman first said they had no record of any aircraft over Amherst, but later said there was something in the air.

Westover chief of public affairs, Lt. Col. James Bishop, confirms that an Air Force C5 cargo plane (pictured above) took off from the base around 5:30 p.m. on the evening of the UFO reports.

"It went out of the area and returned later and flew again in the local area until about 9:30 p.m.," Bishop said, according to the Gazette.

The problem with all of this is that the C5 Galaxy cargo plane is one of the world's largest aircraft. While it might be construed as a triangle-shape aircraft when it banks in certain ways, even Bishop confessed that eyewitnesses probably didn't mistake the very loud C5 for the UFO.

"There's just no mistaking that. It's quite a loud sound and quite a big aircraft," Bishop said.

So, at this point, both the Air Force and FAA aren't trying to convince the public that the C5 was the low-flying, silent, diamond-shaped object seen in the sky on Jan. 8.

So far, there's no official explanation.