If all reports were of a single object, in the knowledge of this investigator no man-made object could have been large enough and far enough away for the approximate simultaneous sightings. It is most unlikely, however, that so many separated persons should at that time have chanced on Venus in the daylight sky. It seems therefore much more probable that more than one object was involved.
The sighting might have included two or more balloons (or aircraft) or they might have included Venus and balloons. For reasons given above, the latter explanation seems more likely.
Two things stand out in his report:
1. The obvious determination to fit some explanation, no matter how farfetched, to the Mantell sighting.
2. The impossibility that Venus—a tiny point of light, seen only with difficulty—was the tremendous metallic object described by Mantell and seen by Godman Field officers.
With Venus eliminated, I went to work on the balloon theory. Since I had been a balloon pilot before learning to fly planes, this was fairly familiar ground.
Shallett’s alternate theory that Mantell had chased a Navy research balloon was widely repeated by readers unfamiliar with balloon operation. Few thought to check the speeds, heights, and distances involved.
Cosmic-ray research balloons are not powered; they are set free to drift with the wind. This particular Navy type is released at a base near Minneapolis. The gas bag is filled with only a small per cent of its helium capacity before the take-off.
In a routine flight, the balloon ascends rapidly to a very high altitude-as high as 100,000 feet. By this time the gas bag has swelled to full size, about l00 feet high and 70 feet in diameter. At a set time, a device releases the case of instruments under the balloon. The instruments descend by parachute, and the balloon, rising quickly, explodes from the sudden expansion.
Occasionally a balloon starts leaking, and it then remains relatively low. At first glance, this might seem the answer to the Kentucky sightings. If the balloon were low enough, it would loom up as a large circular object, as seen from directly below. Some witnesses might estimate its diameter as 250 feet or more, instead of its actual 70 feet. But this failure to recognize a balloon would require incredibly poor vision on the part of trained observers—state police, Army M.P.’s, the Godman Field officers, Mantell and his pilots.