On 7 November 2006, around 4:30 PM, a United ramp worker pushing a plane back from Gate C17 looked up and saw a dark gray, disc-shaped object hovering silently beneath the ~1,900 ft overcast. Within minutes, mechanics taxiing a 777, supervisors, and the pilots of the 737 near C17 were watching too. Size estimates based on witness accounts ranged from 6 to 24 ft, with no lights and no sound. After several minutes it reportedly shot straight up through the clouds, leaving a clear hole that clos...