This article was published on page 24 in the daily newspaper The Cincinnati Post, Ohio, USA, on october 18, 1973.
By B.J. Gilley
INDIANAPOLIS (UPI): For less than a dollar in parts and a couple of hours of labor, anyone can have his own UFO of the type that has been causing flurries of calls to law enforcement officers across East Central Indiana.
Reports of "unidentified flying objects" some of them even tracked on radar, have come from a wide variety of sources, but at least one has proven to be a prank set up by person or persons unknown- a three-color hot air balloon made of paper.
Law enforcement officers fear that the use of the devices as mysterious shining objects in the sky will get more numerous as the traditional season nears for ghosts, goblins and tricks. They point out that the flood of calls they receive from excited persons who have spotted what they think is a "flying saucer" can cause police to be delayed in answering serious complaints of trouble.
The Hamilton County sheriff's department at Noblesville is hanging on to its "spaceship" which landed in the backyard of a home in the southern part of the county on October 2.
The craft measured six feet by two feet and was made with a wire frame over which was stretched purple, orange and green paper of the type used for model airplane wings. Instead of having nuclear engines capable of achieving interstellar drive, it was kept aloft by a candle mounted in the mouth of the sack-like structure.
Hamilton sheriff's deputies said it landed because the candle had burned out, but otherwise the balloon was in good shape for another flight- if the owner cared to claim it at the department's property room.
Robert L. Swaim, professor of aeronautics and astronautics at Purdue University, while noting he was more familiar with designing airplanes, said the description of the Hamilton County UFO was that of a "miniature hot-air balloon." He said that while weather observations balloons sometimes set off flurries of UFO reports, the latest group seemed to be the work of pranksters.
"Weather balloons are filled with helium- similar to balloons released at football games and the Indianapolis 500- so they are lighter than air and will float upward until they reach a point that the internal pressure of the gas causes them to burst or the air is thin enough they won't go any higher," he said. He said whether the balloon would burst or not would depend on the material from which it was made and the amount of helium put into it.
But these seem to be some sort of airborne device which heats the air trapped inside the bag with a small scale heating device similar to those used to lift hot-air balloons under which people can travel," Swaim said. He added that they cannot go up indefinitely because the upper levels of the air would not support combustion needed to keep the air inside the balloon hot. "They use the relative density of the air inside to rise, but air farther away from the earth is less dense and therefore gives them less support," he said.
The hot-air balloon would have nothing in it that would cause radar to pick it up, but Swaim suggested that strips of aluminum foil fastened to the sides of the bag would reflect radar waves while not adding to the weight of the craft.
"The military has used little strips of aluminum foil called chaff to jam radar for years," he noted. "It is released at high altitudes and is find enough that it stays airborne for hours to mask the presence of jets."
Many observers who have reported UFOs have commented on the particular glow that comes from them, often accompanied by a changing pattern of lights. Swaim said this might be caused by light from the heating element bouncing off something inside the air sack, such as aluminum foil.
"If balloons were made out of paper, a light burning at the bottom of it would cast a glow around the entire thing, like an Oriental lantern," he said.
