2001-07-29 - Downers Grove, IL - Changing

The vehicle didn't have the same dark silouette as other aircraft in the area, including aircraft near the objects altitude.

We ( along with several people at a shopping center parking lot ) observed a vehicle at about 7,500 to 10,000 feet, travelling southwest to northeast at a approximate speed of 250 - 300 knots. The object was cylinderical in shape and changed to oval as it moved. We noticed a bright glowing orange/gold color not present in other aircraft in the viscinity at the time. There were several aircraft in the area at the time, inbound to O'Hare from our west/southwest position, and outbound and heading west from Midway at our east position. All jet aircraft in the area were a darker silouette, that the vehicle in question ( with landing lights, anti-collision lights and flying a specific pattern.) The object did not appear to have any wings or tail stabilizer and at once I thought that it looked like the slender silouette of an MD-80. But all at once it changed shape to oval and stopped! Right there about 7,500 to 10,000 feet, appearing to watch the commercial traffic! To add to the mystery, we noticed an eastbound twin-engine aircraft crusing at at least 35,000 feet and for a brief moment, the object blocked our view to to the contrail of the eastbound crusing aircraft. An outbound 757 from Midway passed our position, and the object began to move again, northeast, same altitude. In a matter of seconds it dissapeared.