Large white UFO seen over Chicago in 1956

Summary

In August 1956, a witness in Chicago, Illinois, observed a very large and white object at around 4,000 feet altitude. The object remained visible for five minutes and showed no movement, drawing the attention of the observer. Although several explanations were considered, such as balloons or aircraft, no definitive conclusion was reached. The description and context of the sighting suggested the possibility of an advertising balloon, but the lack of clear information left other interpretations open.

The report, part of Project 10073, includes weather data and a preliminary assessment that failed to identify the object with certainty. This case is an example of how UFO sightings often raise more questions than answers, even with detailed records.