The Voreppe Luminous Disc (GEPAN case 76305443)

In 1976, France had no official office for UFO reports. That changed the following year. The national space agency, CNES, created GEPAN, a small unit run by Claude Poher from 1977 to 1979. It later became SEPRA, and then GEIPAN. Among the files in its records is case 76305443, the account of a scientist driving home.

November 5, 1976. A French physicist was driving home towards Grenoble. The records name the witness only as Dr. S. The road passed near Voreppe. Here the Chartreuse and Vercors massifs meet at the Isère valley, and the mountains rise close on either side.

Then Dr. S. saw it. A "luminous disk moving in the sky." It was "slightly flattened." It was "brighter than the full moon."

The disk moved between the mountains. For a physicist, that was a gift. The ridges gave the light a position. Due to its movement between mountains, it was possible to estimate its distance as lying between 9 and 36 kilometers. It was moving at an altitude of 1,500 to 2,500 feet.

Dr. S. was not alone. According to Jacques Vallée's account of the GEPAN investigation, a similar object had been seen three hours earlier, about eighteen miles east of Rives. It was leaving a trail.

Two hours after the Voreppe sighting, a bright disk was reported far to the west. The witness was the civilian traffic controller in the tower of the military airport at Aulnat, at Clermont-Ferrand. In all, several people reportedly witnessed the same phenomenon. Their reports fell along a straight line stretching over 250 kilometers, from Clermont-Ferrand to Grenoble.

GEPAN gathered these reports under case 76305443. Today, GEIPAN's public catalogue lists a case "Rives (38) 05.11.1976" in Isère as class C, with the reason "Manque d'informations fiables", lack of reliable information. The entry was last updated on 30 May 2011. It is very likely the same file, though that link has not been confirmed. In GEIPAN's system, class C means the case cannot be judged for lack of data, not that it was explained.

In 1998, Vallée took up the case in the Journal of Scientific Exploration. His paper, "Estimates of Optical Power Output in Six Cases of Unexplained Aerial Objects with Defined Luminosity Characteristics," studied six cases "observed by qualified observers over a twenty-year period in various parts of the Earth and in known physical conditions," with estimates "ranging from a few kilowatts to thousands of megawatts." Voreppe, with its trained witness and its mountain geometry, was one of the six.

No one has alleged a hoax. No source has proposed a specific conventional explanation either. A bright meteor could leave a trail. But the reports are spread over about five hours, which does not fit a single fireball.

The case lives on quietly. It appears in the English Wikipedia's list of UFO sightings in France. A copy of Vallée's paper circulated among the extras for Richard Thieme's talk at DEF CON 18 in 2010. And Voreppe has a second, unrelated UFO story: a 1998 video that SEPRA attributed to a children's helium balloon. The 1976 disk has no such answer.