The alleged extraterrestrial sighting, described by the French government as "one of the most astonishing observed in France," is among 1,600 UFO case files spanning the last half-century that the country's space agency opened to the public for the first time Thursday.
Within three hours of posting the first cases Thursday morning, the French space agency's Web server crashed, overwhelmed by the flood of viewers seeking the first glimpses of official government evidence on a subject long a target of both fascination and ridicule.
The material dates as far back as 1954. Over the next several months, the space agency will post it to enhance scientific research seeking to explain what the French government calls "unexplained aerospace phenomena."
"The data that we are releasing doesn't demonstrate the presence of extraterrestrial beings," said Jacques Patenet, who heads the Group for the Study and Information on Unidentified Aerospace Phenomena, the space agency's UFO investigative team. "But it doesn't demonstrate the impossibility of such presence either. The questions remain open."
Patenet said that among the 1,600 cases to be opened to the public, "a few dozen are very intriguing and can be called UFOs."
Most of the cases were determined to be caused by atmospheric anomalies or mistaken perception of such things as airplane lights, or to be hoaxes. One case file described how investigators proved a man was lying about being abducted by aliens when blood tests failed to show he had recently experienced the weightlessness of space travel.
In one of the cases investigators consider most credible, a 13-year-old boy and his 9-year-old sister were watching over their family's cows near the village of Cussac on Aug. 29, 1967, when the boy spotted "four small black beings" about 47 inches tall, according to documents released Thursday. Thinking they were other youngsters, he shouted to his sister, "Oh, there are black children!"
But as they watched, the four beings became agitated and rose into the air, entering the top of what appeared to be a round spaceship, about 15 feet in diameter, which hovered over the field. Just as the sphere rose up, one of the passengers emerged from the top, returned to the ground to grab something, then flew back to the sphere.
The sphere rose silently in a spiral pattern, then "became increasingly brilliant" before disappearing with a loud whistling sound. It left "a strong sulfur odor after departure," the report said.
The children raced home in tears and their father summoned the local police, who "noted the sulfur odor and the dried grass at the reported place where the sphere took off," the report continued. Investigators said they were impressed by the uniformity of detail provided by the children and other witnesses.
"No rational explanation has been given to date of this exceptional meeting," the investigation concluded.
One of the most detailed inquiries involved the report of an Air France crew flying near Paris on Jan. 28, 1994. Three crew members spotted a large reddish brown disk "whose form is constantly changing and which seems very big in size." As the passenger plane crossed its trajectory, the object "disappeared on the spot," the report said.
Radar signatures confirmed an object of the same size and location described by the crew and led investigators to conclude that "the phenomenon is not explained to date and leaves the door open to all the assumptions."
Patenet, the leader of the space agency's investigative team, said his group receives about 100 new cases a year and usually opens investigations on about 10 percent of them. "In 99 percent of the cases, the witnesses are perfectly sincere," he said. "They saw something. Most of the time what they saw is a perfectly natural phenomenon that has been perceived in an erroneous way."
Patenet said he has never seen a UFO. "I would personally find it abnormal to think that we're the only civilization in the universe, but the probability of various civilizations coming across each other is also very slim."
Researchers Corinne Gavard in Paris and Robert E. Thomason in Washington contributed to this report.
By Molly Moore