CORROBORATED
CF-GEI-19800400764 CORROBORATED
The Bas-Rhin 'Following Ball' Illusion
CASE FILE — CF-GEI-19800400764 — CASEFILES CLASSIFIED ARCHIVE
Date Date when the incident was reported or occurred
1980-04-11
Location Reported location of the sighting or event
Bas-Rhin Department, Alsace, France
Duration Estimated duration of the observed phenomenon
40 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 the night of April 11-12, 1980, between 23:50 and 00:30, four witnesses in the Bas-Rhin department of Alsace observed a luminous phenomenon that appeared to follow their vehicle for over 30 minutes. The object, described as displaying changing colors, appeared stationary when the witnesses stopped and mobile when they drove, creating what investigators term the 'boule suiveuse' (following ball) illusion. Witnesses T2 and T3 consistently placed the object 'above the Liebfrauenberg' (a local château), while T1 referenced 'near the radars of Drachenbronn base.' The phenomenon was documented in gendarmerie reports N°491 and N°307.
Originally classified as 'D' (unexplained) under the name 'SOULTZ SOUS FORETS (67) 1980,' this case was re-examined by GEIPAN using modern astronomical software and accumulated expertise from similar cases. The witnesses reported the object appeared low on the horizon, remained visible for an extended period, seemed to pace their vehicle along the route from Hoelschloch to Merkwiller, appeared to 'contour the church' at Merkwiller, and eventually disappeared behind local terrain. The sky was reported as clear and starry throughout the observation.
GEIPAN's detailed analysis confirmed the object was Venus, which at 23:50 was extremely visible (magnitude -4.4) at azimuth 301° and elevation 6.2°. The witness sightings aligned precisely with Venus's position, and the planet's disappearance matched the calculated terrain masking at approximately 00:20-00:30 when Venus descended behind the Goersdorf forest massif at 4.2km distance. Despite observing for over 30 minutes in a clear sky while looking in Venus's direction, none of the witnesses recognized the planet, leading to the misidentification.
02 Timeline of Events
23:50
Initial Sighting
Multiple witnesses first observe luminous phenomenon in clear, starry sky. Venus is at azimuth 301°, elevation 6.2°, magnitude -4.4.
23:50-00:25
Vehicle Observation Phase
Witnesses travel by vehicle from Hoelschloch to Merkwiller. Object appears to pace vehicle on left side, creating 'following ball' illusion. Object appears to 'contour the church' at Merkwiller as vehicle changes direction.
00:25-00:30
Stationary Observation at Merkwiller
Vehicle stops at crossroads in Merkwiller. Object appears stationary above Liebfrauenberg château. Witnesses T2 and T3 consistently identify this landmark; T1 and T4 reference Drachenbronn base radars.
00:20-00:30
Object Disappearance
Object disappears behind local terrain. Venus calculated to be masked by Goersdorf forest massif at ~00:20 (elevation drops below 2.7° relative angle). T1 reports rapid departure toward Lobsann; T3 mentions yellow trail northward; T2 and T4 do not confirm departure.
Post-incident
Gendarmerie Investigation
Official reports filed (PV N°491 and N°307). Case initially classified 'D' (unexplained) as 'SOULTZ SOUS FORETS (67) 1980.'
Modern era
GEIPAN Re-examination
Case re-analyzed using modern astronomical software and accumulated expertise. Astronomical calculations definitively match Venus. Reclassified as 'A' (identified with certainty) as Venus misidentification with 'following ball' illusion.
03 Key Witnesses
Witness T1
Civilian driver
low
Vehicle occupant during observation. Testimony shows significant discrepancies with other witnesses.
"L'objet se tenait immobile à proximité des radars de la base de DRACHENBRONN. Nous avons observé ce phénomène jusque zéro heure vingt-cinq à laquelle il s'est éloigné à très grande vitesse vers LOBSANN."
Witness T2
Civilian observer
medium
One of multiple witnesses. Provided consistent landmark reference to Liebfrauenberg château.
"Ce dernier est resté jusqu'à 0 heure 30 au dessus du Liebfrauenberg. J'ignore quelle direction il a prise par la suite, je n'ai pas fait attention."
Witness T3
Civilian observer
medium
Witness whose testimony corroborated T2's landmark references. Mentioned military radar installations.
"Je précise que lorsque la boule était au-dessus du Liebfrauenberg, dans cette direction, elle se trouvait très près et juste au-dessus des installations radars de la Base Aérienne, à leur gauche. Cette boule est partie en laissant une traînée jaune, en direction du Nord."
Witness T4
Military serviceman (non-local)
medium
Performing military service in the area. Not originally from the region, which may have influenced landmark identification.
"Nous avons pu observer pendant une demi-heure environ l'objet qui se trouvait apparemment en stationnement au-dessus de la base de DRACHENBRONN."
04 Analyst Notes -- AI Processed
This case represents a textbook example of the 'following ball' illusion, a well-documented perceptual phenomenon when observers misidentify a bright celestial object. GEIPAN's analysis is particularly thorough, employing astronomical calculations, terrain elevation profiles, and witness testimony cross-referencing. The investigation demonstrates several classic hallmarks: (1) Extended observation duration (40+ minutes) with low elevation angle; (2) Perceived movement correlating with vehicle motion while object remains fixed relative to terrain; (3) Failure to identify an extremely bright planet (-4.4 magnitude) despite clear conditions; (4) Color changes and apparent 'jerky' movements consistent with atmospheric refraction at low angles.
Witness credibility varies significantly. Testimonies T2 and T3 show strong concordance in landmark references (Liebfrauenberg château), while T1's account contains notable inconsistencies—describing 'two discs connected by a line,' reporting the object 'high in the sky' when others saw it to the left, and claiming rapid departure toward Lobsann (northeast). T4, a non-local performing military service, appears to have adopted references from other witnesses. The gendarmerie synthesis mentions a final 'flight to the northeast,' but only T1 and partially T3 support this, while T2 and T4 do not. GEIPAN correctly identifies atmospheric dimming as the likely source of perceived 'departure.' The reclassification from D to A demonstrates the value of modern analytical tools and accumulated case experience.
05 Theory Comparison
BELIEVER ANALYSIS
SKEPTIC ANALYSIS
Collective Misperception Reinforcement
Multiple witnesses observing together can reinforce initial misidentification through social confirmation bias. Once the first witness interprets the bright light as anomalous rather than Venus, subsequent observers adopt this framework. The vehicle context amplified the illusion—passengers expect roadside objects to move relative to the car, so when Venus appeared fixed to the vehicle's reference frame, it seemed to be 'following' them. Color changes and apparent motion are purely atmospheric refraction effects at low angles. Witness T1's more elaborate claims (two discs, rapid departure) represent individual embellishment on the shared misperception. The gendarmerie's initial 'D' classification shows even trained investigators can be misled without astronomical verification tools.
06 Verdict
ANALYST VERDICT
GEIPAN's conclusion is definitive: this was Venus. The astronomical data is irrefutable—Venus's position (azimuth ~301°, elevation 6.2°, magnitude -4.4) matches witness directions precisely, and calculated terrain masking aligns with reported disappearance times within acceptable margins of error. The 'following ball' illusion is a well-understood psychological phenomenon where the brain misinterprets the fixed angular position of a distant object as intentional tracking. This case's significance lies not in the phenomenon itself, but in demonstrating how trained gendarmes and multiple witnesses can be collectively deceived by a familiar astronomical object under unremarkable conditions. The re-examination exemplifies proper scientific methodology: GEIPAN transparently shows how initial 'unexplained' classifications can be resolved through rigorous analysis, providing valuable data for understanding witness perception and the mechanics of misidentification. Classification A is fully justified.
AI CONFIDENCE SCORE:
85%
07 Community Discussion
VIEW ALL >// NO COMMENTS YET
Be the first field agent to contribute analysis on this case.
08 Live Chat 1 ROOM
ENTER LIVE CHAT
Real-time discussion with other field agents analyzing this case.