An unidentified flying object over Denver on Monday has aviation experts scratching their heads.

As first reported by 9News, the object did not appear on radar in the area, but nearly collided with a private jet at 8,000 feet above Cherry Creek.

In an audio recording from the jet cockpit, provided by LiveATC.net, a pilot can be heard telling air traffic officials, "[I] don't know if it was a remote controlled aircraft or what, but something just went by the other way. About 20-30 seconds ago... And it was like a large remote controlled aircraft.

LISTEN to audio from the cockpit [via LiveATC.Net]

In March of 2011, residents of nearby Lafayette, Colorado, recorded video of three hovering, seemingly disconnected lights in the sky there.

The three lights remained in a triangular pattern, moving slowly toward the northeast. The Daily Camera reports that when one light extinguished, witnesses say the other two "just turned off and were gone."

In 2010, Denver voters rejected a ballot measure that would've created a commission to track extraterrestrials. The proposal was the brainchild of Jeff Peckman, who gained fame in 2008 after claiming to have video of a live alien peeking through a window in Nebraska.

