It is noteworthy that the investigation by GEPAN disclosed that a similar object had been seen three hours earlier about eighteen miles east of Rives, leaving a trail, and that a bright disk was seen two hours later by the civilian traffic controller in the tower of the military airport at Aulnat. Shortly after 8:05 P.M. that same day a witness located a few miles away near Vienne saw a slightly flattened sphere, whose light was similar to that of a very bright neon tube, with a fiery red-orange area underneath. It was about one-sixth of the diameter of the full moon and was flying very fast from the west-northwest to the east-southeast.

Given these detailed, competent observations, it is possible to bracket the energy and speed of the object with some reasonable numbers. From a careful reconstruction of the sighting it was estimated that the object was flying at an altitude of 1,500 to 2,500 feet, which would give it a diameter between six and twenty feet and a speed approximating one mile per second, or 3,600 miles per hour, during the second phase of its trajectory. Assuming that the disk gave off as much light as the full moon, as observed by Dr. Serge, its energy in the visible part of the spectrum was a modest 15 kW. This is only a minimum value, based on the assumption that the landscape directly underneath the object was illuminated with an intensity comparable to that of the full moon. If illumination at the much greater distance where Dr. Serge was located was also that of the full moon we would be in conditions similar to those of case no. 2, with a much higher power output value.

In the detailed interviews conducted by investigators of the French National Center for Space Studies (CNES), Dr. Serge expanded on his description of the object, noting that the halo reminded him of the color produced by the combustion of copper salts. It is also noteworthy that Dr. Serge, who serves as director of a nuclear physics laboratory, did not report the sighting to anyone and did not mention it to his colleagues. It was only when the observation by Miss M. and her father was mentioned in newspapers that he volunteered his own experience. It should be noted further that, in addition to the reports from the gendarmes, the letters from the witnesses, and the investigations by GEPAN scientists, several of the observers were interviewed in person by a judge, a former president of the regional Court of Appeals.

Case no. 5: June 19, 1978. Gujan-Mestras (France) -- Classification: MA-2

This incident took place near Arcachon in France on June 19, 1978, and was also investigated in depth by GEPAN.⁹ While the Grenoble case was remarkable for the convergence and high quality of the observations, the present case introduces another exceptional parameter: the UFO triggered the photocells that control the lights for the whole town. From the distance and the threshold