The summer after The Day the Earth Stood Still

The summer after The Day the Earth Stood Still was released, however, Washington experienced an incident that may have made some people wonder if the movie was totally fictitious. Just before midnight on July 19, 1952, an air traffic controller at Washington National Airport spotted seven unidentified objects on the radar screen, about 15 miles to the southwest of the District.  "Here's a fleet of flying saucers for you," he jokingly told his supervisor, according to a newspaper account. But officials became alarmed when a second controller at another facility revealed he not only had the objects on his screen, but could see "a bright orange light" through the window of his control tower. Shortly after that, an airman at Andrews Air Force Base  reported seeing a strange orange ball of fire, similar to what one of the controllers had described, followed by a second ball. At 12:30 a.m., one of the objects buzzed a runway at National, and another controller got a glimpse of it. He described it as an orange disk, and said that it hovered at 3,000 feet (914 meters) over the airport before disappearing.  Military jets from a base in Delaware were scrambled to chase down the apparent intruders, but the objects just as mysteriously vanished, though just before dawn, another witness again briefly saw what he described as five large disks, flying in loose formation.
After what appeared to be similar UFOs appeared again on July 26, President Harry Truman called Air Force Capt. Edward J. Ruppelt, supervisor of the military's then-secret Project Blue Book, an investigation of UFO reports. Ruppelt concluded that the objects on the radar screen were false readings caused by trapped layers of warm air in the atmosphere, but UFO enthusiasts have never accepted that explanation.