CORROBORATED
CF-GEI-19811200902 CORROBORATED

The Pontvallain Trapezoidal Light - Moon Reflection Case

CASE FILE — CF-GEI-19811200902 — CASEFILES CLASSIFIED ARCHIVE
Date Date when the incident was reported or occurred
1981-09-05
Location Reported location of the sighting or event
Pontvallain, Sarthe, Pays de la Loire, France
Duration Estimated duration of the observed phenomenon
10 minutes
Object Type Classification of the observed object based on witness descriptions
light
Source Origin database or archive this case was sourced from
geipan
Witnesses Number of known witnesses who reported the event
4
Country Country where the incident took place
FR
AI Confidence AI-generated credibility score based on source reliability, detail consistency, and corroboration
85%
On September 5, 1981, at approximately 23:00 hours, four witnesses in Pontvallain observed an unusual luminous phenomenon in a pine grove near their residence. The light appeared trapezoidal in shape and displayed high intensity for approximately 10 minutes before abruptly extinguishing. No sound accompanied the phenomenon. When the local gendarmerie brigade arrived at 23:45, they found no trace of the light. The following day, investigators discovered a circular area of flattened ferns, measuring 20-30 cm in diameter, all bent in the same direction. This ground trace initially suggested something anomalous had occurred at the site. The gendarmerie conducted a follow-up observation the next evening from the same location to attempt to replicate the phenomenon. The investigation concluded with a definitive explanation: the gendarmerie determined that the trapezoidal light was caused by moonlight shining through the pine trees, creating an unusual optical effect. The ground traces were subsequently attributed to forestry equipment that had been operating in the area. GEIPAN classified this case as 'A' - fully explained with certainty.
02 Timeline of Events
23:00
Initial Observation
Four witnesses observe a trapezoidal-shaped light of high intensity in a nearby pine grove. The phenomenon appears stationary and emits no sound.
23:00-23:10
Extended Observation Period
Witnesses continue observing the bright trapezoidal light for approximately 10 minutes. The phenomenon maintains consistent appearance throughout.
23:10
Light Extinguishes
The luminous phenomenon abruptly disappears. Witnesses report authorities.
23:45
Gendarmerie Arrival
Local gendarmerie brigade arrives on scene but observes no luminous phenomenon. Site appears normal.
1981-09-06 (day)
Ground Investigation
Investigators discover a circular area of flattened ferns (20-30 cm diameter) with all plants bent in the same direction, suggesting physical disturbance.
1981-09-06 (evening)
Recreation Experiment
Gendarmerie returns to the exact location at the same time. Officers observe and confirm that moonlight shining through the pine trees creates the trapezoidal light effect.
Post-investigation
Ground Trace Explanation
Follow-up investigation establishes that the circular fern traces were caused by forestry equipment operating in the area, not related to the light phenomenon.
03 Key Witnesses
Anonymous Witness Group
Civilian residents
medium
Four local residents near Pontvallain who observed the phenomenon from their home near a pine grove
"No direct quotes available from witness testimony"
04 Analyst Notes -- AI Processed
This case demonstrates the value of systematic investigation and on-site recreation of reported phenomena. The gendarmerie's decision to return to the exact location the following night at the same time proved crucial in identifying the mundane explanation. The trapezoidal shape reported by witnesses is consistent with moonlight filtering through gaps in pine tree canopy, which can create geometric patterns of light and shadow. The ground traces added an intriguing element that could have elevated this case's mystery, but thorough investigation revealed forestry equipment as the source. The witnesses' credibility is not questioned - they genuinely observed what they reported. However, this case illustrates how unfamiliar natural phenomena, especially unusual light effects in familiar environments, can be misinterpreted as anomalous. The abrupt 'extinguishing' of the light likely corresponded to the moon's position changing relative to the tree canopy or cloud cover. The 15-minute delay before gendarmerie arrival (23:00 sighting, 23:45 arrival) allowed sufficient time for lunar position to shift, explaining why officers saw nothing upon initial response.
05 Theory Comparison
BELIEVER ANALYSIS
SKEPTIC ANALYSIS
Misidentification with Unrelated Ground Traces
This case represents a textbook example of how unusual but natural phenomena can be misinterpreted as anomalous when observed in unfamiliar contexts. The witnesses genuinely saw moonlight creating an unusual geometric pattern, but lacking familiarity with such optical effects in their local environment, interpreted it as extraordinary. The ground traces added false corroboration but were actually unrelated forestry activity. The human tendency to seek patterns and connections led to these separate mundane events being linked into a single 'mysterious' incident.
06 Verdict
ANALYST VERDICT
This case is definitively explained as a misidentification of moonlight filtered through pine trees, creating an unusual trapezoidal light pattern. Confidence level: very high. The gendarmerie's recreation of the phenomenon the following night provides direct observational confirmation. While the case lacks significance as a genuine UAP event, it serves as an excellent example of thorough investigative methodology and the importance of on-site verification. The GEIPAN 'A' classification is fully justified. This case is valuable for training purposes, demonstrating how environmental factors and natural phenomena can create compelling but ultimately mundane observations.
AI CONFIDENCE SCORE:
85%
07 Community Discussion
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