Why Essonne’s UFO Files Usually Come Back to Earth

Why Essonne produces UFO reports without producing many strong mysteries

Essonne sits in an observationally busy part of France. It includes dense urban zones, open countryside, major roads, high-rise viewpoints, research and technology districts, and the southern edge of the Paris aviation environment. That matters because many UFO reports are not generated in empty skies: they are generated when ordinary objects are seen from awkward angles, in poor light, under surprise, from a moving vehicle, or near flight paths. GEIPAN’s own classification system is designed to separate four broad outcomes: A for a phenomenon identified after investigation, B for a probable identification, C for a case left unidentified because the information is insufficient, and D for a phenomenon still unidentified after investigation.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr. Overview image for Why Essonne's UFO Files Usually Come Back to... For Essonne, the public GEIPAN record currently points less towards a concentration of unresolved high-strangeness cases than towards a pattern of reported anomalies that become understandable once direction, timing, astronomy, weather and local aviation are checked. This is important: an explained case is not the same as a foolish witness. Several Essonne witnesses were observant, concerned and specific. The later explanation often rests not on dismissing them, but on reconstructing what the sky looked like from their exact position. GEIPAN says its classification method weighs both “consistency” — how reliable and objective the available information is — and residual “strangeness” after investigation.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The result is a department-level UFO history with three recurring themes:<div class="content-enhancement content-enhancement--insight-grid" markdown="1">

Aviation geometry, especially around Athis-Mons and the Paris-Orly environment.[runwaydirectionforecast.com]runwaydirectionforecast.comSource details in endnotes.
Astronomical misidentification, especially Venus or a low, orange Moon.
Modern light objects, including LED balloons, festive balloons and lanterns.</div>

That pattern does not make Essonne uninteresting. It makes it a good case study in how a sober UFO archive is built: witness first, hypothesis second, classification last.

The Athis-Mons problem: when aircraft look stranger than aircraft

Athis-Mons is one of the most instructive names in Essonne’s UFO file because it appears in both weakly documented and more recently analysed cases. The 14 September 1980 report is intriguing on its face: an air traffic controller on duty reportedly saw a black cylindrical object overhead at about 12.45 pm. It was described as stationary at roughly 300 metres above the ground, then accelerating sharply and disappearing eastwards. GEIPAN classifies the case as C, not as a confirmed unexplained craft, because no information allowing a serious study was gathered.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

That distinction is crucial. A witness with aviation experience sounds stronger than an ordinary passer-by, but a C classification means the case lacks enough usable data. There is no secure chain of corroboration, no detailed reconstruction strong enough to test competing explanations, and no identified object. For public UFO history, this makes the case worth noting but not worth overstating. It is one of Essonne’s more memorable reports because of the witness role and the “cylindrical black object” description; it is also one of the weaker evidential cases because the file did not produce the data needed to investigate it properly.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The 30 July 2016 Athis-Mons case shows the other side of the same local problem. A witness stopped at a traffic light on the RN7 near Paris-Orly observed a very bright round object, likened to a ping-pong ball, which seemed stationary before moving and then disappearing quickly in a straight line. GEIPAN classified the case as B: probably an aircraft approaching Paris-Orly, with landing lights seen almost along the aircraft’s line of travel. The apparent “stillness” followed by rapid motion was treated as a perspective effect: when an aircraft approaches nearly head-on, its angular movement can seem minimal, then suddenly increase as the viewing angle changes.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

This 2016 case matters because it gives readers a practical key to many airport-adjacent UFO reports. The witness was not inventing the brightness, the apparent roundness or the sudden motion. The interpretation changed because the viewing geometry changed. GEIPAN also noted the immediate proximity of Orly and the constant aviation security surveillance in that zone; the lack of exploitable radar data prevented identification of the exact aircraft, but not the probable class of object.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr. Why Essonne's UFO Files Usually Come Back to... illustration 1

The Moon and Venus cases are not trivial mistakes

Some of the clearest Essonne cases involve astronomical objects. They are easy to mock after the fact, but that would miss why they matter. The Moon and Venus can become strange in real observing conditions: low on the horizon, partly masked by cloud, seen from a balcony, observed through tiredness, or watched while the observer is moving.

On 23 and 25 August 1980, a witness in Épinay-sous-Sénart reported a very bright point in the eastern sky during long early-morning observations. On the second date, the observation reportedly lasted around two hours and involved binoculars. GEIPAN re-examined the case, noting that the earlier GEPAN file had already considered Venus probable. The modern classification is A: a misidentification of Venus, which was especially bright and in the relevant part of the sky.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The point is not that “any light is Venus”. It is that long duration, fixed position, brilliance, a star-like appearance and a night-time emotional impression can combine to make a normal planet feel abnormal. GEIPAN explicitly states that the witness’s sincerity and credibility were not in doubt; the issue was the interpretation of a real perception. That language is useful for the whole Essonne archive because it separates witness honesty from explanatory accuracy.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

A similar lesson appears in the Villebon-sur-Yvette case of 6 September 1982. A couple on a third-floor balcony saw a large orange luminous form, compared to a saucer or airship, low towards the Orly runway direction. The case had previously been treated as more puzzling, but GEIPAN later reclassified it as A after concluding that it matched the Moon near moonrise. The report highlights several factors: the orange colour, large oval appearance, low angular height, possible cloud near the eastern horizon, and an apparent disappearance or movement caused by cloud masking and interpretation.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The most recent example is even more direct. On 1 January 2026, between Briis-sous-Forges and Limours, a driver saw a yellow-orange luminous sphere at low apparent altitude that seemed to move and then vanish behind the horizon. GEIPAN classified the case as A: the Moon in its setting phase. The analysis compared the witness’s direction and angular estimates with astronomical data and explained the impression of the object “accompanying” the vehicle as a perspective effect: the Moon’s apparent position changes very little as nearby landscape moves past.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

Together, these cases show one of Essonne’s strongest patterns. The department’s UFO history is not just a list of lights in the sky; it is a record of how ordinary celestial objects become extraordinary when seen low, orange, bright, partially obscured or framed by urban and road environments.

Balloons, lanterns and lasers: the modern Essonne pattern

From the mid-2010s onward, several Essonne cases fit a modern category that older UFO catalogues did not have to handle as often: small, illuminated consumer objects. These can look surprisingly structured, silent and self-propelled, especially at night or during festive periods.

On Christmas Eve 2015 in Évry, three people saw a silent luminous object with changing colours — green, blue and orange — pass overhead for about 45 seconds before disappearing behind a building. GEIPAN classed it as B, probably a festive LED balloon. The reasoning was practical: a low-altitude, silent, multicoloured object on a festive evening, moving compatibly with wind data from Orly, fits a lighter-than-air object better than a structured craft.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

On 1 January 2016 at Villemoisson-sur-Orge, GEIPAN recorded a B classification with the phenomenon type given as a sky lantern. The date matters: New Year celebrations are a common context for lanterns, small balloons and other low-speed lights that can drift silently and vanish without leaving a conventional aircraft signature.[Geipan]geipan.frOpen source on geipan.fr.

Palaiseau’s 17 February 2022 case is another useful example because it received a more developed investigation. GEIPAN classified it as B, with the phenomenon type “LED balloon”, and the associated investigation considered how a balloon might disappear suddenly, including the possibility of bursting. The case also shows a typical evidential limitation: without identifying every nearby aircraft or fixing the object’s exact distance, witness estimates of size remain uncertain.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

Villejust, recorded on 29 August 2017, appears in GEIPAN’s case list as an A-classification laser case. That is a small entry, but an important reminder: not every strange light is airborne at all. Some “sky” observations are caused by projected light, reflections or ground-based illumination.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

These modern cases matter because they reduce the temptation to read every silent light as advanced technology. A small object with no engine noise, changing colours and odd motion can be much less exotic: light wind, low altitude, LEDs, balloons, lanterns or a beam. The harder task is not imagining a spectacular explanation, but checking whether the simple one accounts for the whole observation. Why Essonne's UFO Files Usually Come Back to... illustration 2

The thin cases: why “unidentified” often means “not enough to work with”

Several Essonne records remain unsatisfying because the data are too thin. That does not mean they are strong mysteries. In GEIPAN’s terminology, a C case is not identified because of lack of data or information, not because it resisted a full investigation with strong evidence.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The Athis-Mons report of 24 August 1979 is one such file. GEIPAN lists it as C, with the phenomenon type described as lack of reliable information, and the available documents include a witness photograph and questionnaire. The public summary does not provide enough detail to turn it into a robust department landmark.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The A10 Janvry-to-Paris observation of 27 October 2007 is another useful weak case. An automobilist saw a fast luminous phenomenon with a persistent smoke trail moving north-east; the event lasted only one or two seconds. The witness suspected a meteorite, and GEIPAN considered that probably correct, but classified it as C because the description was too brief to confirm.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

Yerres, 8 December 1983, appears in GEIPAN’s tabulated public listing as another Essonne C case, again in the “lack of reliable information” category. Saint-Hilaire, 4 October 1981, also appears in GEIPAN search results among Essonne C-class cases. These entries are part of the department’s record, but they should not be inflated into major incidents unless fuller documentation emerges.[Geipan]geipan.frOpen source on geipan.fr.

For readers, the lesson is simple: “unidentified” is not one category. A case may be unidentified because it is genuinely puzzling after a serious investigation, or because the file is too incomplete to decide. Essonne’s public record contains more of the latter than the former.

The 1954 wave in present-day Essonne

Essonne did not exist as a department in 1954; it was created later from the old Seine-et-Oise structure. That makes older UFO history awkward, because many 1954 reports are indexed under present-day Essonne towns only retrospectively. Still, those reports matter because the great French wave of 1954 is a major strand of national UFO history, and several present-day Essonne localities appear in later catalogues.

The most accessible specialist catalogue work lists 22 September 1954 reports around Saint-Chéron, La Norville, Arpajon and Montgeron, often as nocturnal lights with possible meteor or Venus explanations rather than strong close-encounter evidence. Patrick Gross’s 1954 catalogue, for example, treats Saint-Chéron as a possible meteor case and Montgeron as probably Venus; its Arpajon page also flags the possibility of duplication or second-hand catalogue inflation.[ufologie.patrickgross.org]ufologie.patrickgross.orgOpen source on patrickgross.org.

Milly-la-Forêt appears in accounts of 3 October 1954, with a restaurateur reportedly seeing a red cigar-like or half-moon form accompanied by a bright ring for several minutes. That is a more colourful story, but it is still an archive-dependent account rather than a modern investigated case with instrument data. Gross’s page preserves the report and cites period ufological and press references, but it should be read as historical folklore-plus-testimony, not as a settled physical event.[ufologie.patrickgross.org]ufologie.patrickgross.orgOpen source on patrickgross.org.

This is where balance matters. The 1954 material gives Essonne a place in the national French UFO wave, but the evidential standards are uneven: old press snippets, later catalogues, changed administrative boundaries, repeated entries, uncertain times and occasional probable conventional explanations. The historical value is real; the proof value is limited.

The 5 November 1990 re-entry and the Essonne afterlife

The national event of 5 November 1990 is relevant to Essonne because it shaped French UFO discussion for decades and appears in later Essonne-linked debates. GEIPAN describes the event as a spectacular luminous phenomenon seen from around 7 pm by more than a thousand witnesses across France, with many reports coming through the Gendarmerie. GEIPAN’s later simulation and public treatment identify it as an atmospheric re-entry, specifically the kind of wide, long-duration event that can generate many local “UFO fleet” impressions at once.[cnes-geipan.fr]cnes-geipan.frsimulation rentree atmospherique 1990simulation rentree atmospherique 1990

Essonne enters this story through local and ufological afterlife rather than through a single decisive official Essonne case. Brétigny-sur-Orge, Montgeron, Linas and Vert-le-Grand appear in sceptical discussions of disputed 1990 interpretations, especially around claims that some local observations were incompatible with a simple re-entry. One sceptical reconstruction argues that several supposedly anomalous local cases can still be read as distorted observations of the re-entry, affected by fear, viewing conditions, memory, reporting changes or geographical errors.[univers-ovni.com]univers-ovni.comOpen source on univers-ovni.com.

This matters because the 1990 event shows how a real sky phenomenon can become a UFO controversy even after a strong conventional explanation exists. A re-entering rocket body or debris cloud is not a point-like meteor. It can appear large, slow, fragmented, silent and structured. Witnesses may disagree about direction, size or duration, especially when watching from different locations and retelling the event later. For Essonne’s UFO history, 5 November 1990 is less a local “case” than a warning about mass sightings: many sincere reports can share one physical cause while still producing contradictory local narratives.[cnes-geipan.fr]cnes-geipan.frsimulation rentree atmospherique 1990simulation rentree atmospherique 1990

What the Essonne record says overall

Essonne’s UFO history is best understood as a test of interpretation. The department has enough reports to show recurring patterns, but not enough strong unresolved evidence to justify a dramatic mystery narrative. Its most useful cases are the ones that teach readers how investigation changes the story.

The strongest explained cases are the astronomical and aviation cases: Épinay-sous-Sénart with Venus, Villebon-sur-Yvette and Briis-sous-Forges/Limours with the Moon, and Athis-Mons 2016 with an aircraft approach. These files are valuable because GEIPAN gives concrete reasons, not just labels: direction, timing, brightness, low angle, cloud, perspective and local flight context.[cnes-geipan.fr+3cnes-geipan.fr+3cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The most interesting weak case is probably Athis-Mons 1980, because of the reported black cylinder and the aviation-controller witness. But it remains weak precisely because the official file says no information allowing a serious study was gathered. It is a memorable report, not a solved mystery and not a demonstrated extraordinary event.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The most modern pattern is the rise of small illuminated objects: LED balloons, festive balloons, sky lanterns and lasers. Évry 2015, Villemoisson-sur-Orge 2016, Villejust 2017 and Palaiseau 2022 show how low-speed, silent, coloured or drifting lights can generate UFO reports without requiring unusual craft.[cnes-geipan.fr+3cnes-geipan.fr+3Geipan]cnes-geipan.frOpen source on cnes-geipan.fr.

The historical layer is the 1954 wave and the 1990 re-entry controversy. These connect Essonne to broader French UFO history, but they should be handled carefully. The 1954 reports are historically interesting but often dependent on old press and later catalogue work; the 1990 event is nationally important but officially explained as an atmospheric re-entry, even though some local retellings continued to dispute or complicate that explanation.[ufologie.patrickgross.org+2ufologie.patrickgross.org]ufologie.patrickgross.orgOpen source on patrickgross.org. Why Essonne's UFO Files Usually Come Back to... illustration 3

How to read an Essonne UFO claim today

A good reader’s rule for Essonne is to ask what kind of case is being discussed before asking whether it is “real”. A GEIPAN A case is identified. A B case is probably identified. A C case is not a strong mystery by default; it may simply lack usable information. A D case would carry more residual weight, but the public Essonne material surfaced here is dominated by A, B and C examples rather than well-documented D-class anomalies.[cnes-geipan.fr]cnes-geipan.frOpen source on cnes-geipan.fr.

The most useful questions are practical:<div class="content-enhancement content-enhancement--metric" markdown="1">

Where was the witness facing? Low eastern or western horizons are especially important for the Moon, Venus and aircraft lights.
Was the witness moving? Cars can create powerful perspective effects, especially with the Moon or distant lights.
Was the case near Orly or a flight corridor? Aircraft seen head-on can look stationary, round and unusually bright.
Was it a festive date? Christmas Eve and New Year reports invite balloon and lantern checks.
How long did it last? A one-second streak is a different kind of case from a two-hour light.
What did later investigation add? Re-examined cases can move from puzzling to explained when better software, sky data or experience is applied.</div>

Essonne therefore matters not because it proves extraordinary visitation, but because it shows the real texture of French UFO investigation at local level: sincere witnesses, strange first impressions, official files, old catalogue echoes, occasional weak data, and many explanations that only become obvious after the sky is reconstructed.

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Endnotes

1. Source: insee.fr
Title: 91 essonne
Link:https://www.insee.fr/fr/metadonnees/geographie/departement/91-essonne

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3. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/node/412

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Link:https://www.cnes-geipan.fr/en/node/58788

5. Source: cnes-geipan.fr
Title: methodologie classification geipan
Link:https://www.cnes-geipan.fr/en/actualites/methodologie-classification-geipan

6. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/fr/cas/1980-09-00802?field_agregation_index_value=&field_classification_des_cas_target_id%5B13%5D=13&field_classification_des_cas_target_id%5B14%5D=14&field_classification_des_cas_target_id%5B15%5D=15&field_classification_des_cas_target_id%5B16%5D=16&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=1&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=57.70414723434193&field_latitude_value%5Bmin%5D=19.642587534013032&field_longitude_value%5Bmax%5D=49.921875&field_longitude_value%5Bmin%5D=-9.843750000000002&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=13%2C24&select-category-export=nothing&sort=asc&video=on

7. Source: cnes-geipan.fr
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Link:https://cnes-geipan.fr/fr/cas/1980-08-01688

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Link:https://cnes-geipan.fr/fr/cas/2026-01-51730

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Link:https://www.cnes-geipan.fr/fr/cas/2015-12-09391?field_is_new_value=1&field_is_revisited_value=All&field_type_de_cas_target_id=All&order=field_departement_textuel&page=18%2C27&sort=desc

12. Source: geipan.fr
Link:https://geipan.fr/fr/temoignage/8912

13. Source: geipan.fr
Link:https://www.geipan.fr/en/node/59676?field_classification_des_cas_target_id%5B0%5D=12&page=8%2C6

14. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/en/node/60502

15. Source: cnes-geipan.fr
Title: Compte rendu enquete655
Link:https://cnes-geipan.fr/sites/default/files/Compte%20rendu%20enquete655.pdf

16. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=Ain&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=51&sort=desc

17. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/fr/cas/1979-08-08386

18. Source: geipan.fr
Link:https://www.geipan.fr/fr/recherche/cas/tab?field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_type_de_cas_target_id=All&order=field_classification_des_cas&page=19&sort=desc

19. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/fr/cas/2007-10-02481

20. Source: cnes-geipan.fr
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Link:https://ufologie.patrickgross.org/1954/1oct1954ligescourtf.htm

25. Source: cnes-geipan.fr
Title: simulation rentree atmospherique 1990
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Link:https://www.cnes-geipan.fr/en/recherche/cas/tab?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=127%2C35&sort=desc&undefined=

33. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/search/cas?field_agregation_index_value=orange&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_date_d_observation&page=16%2C0&sort=asc

34. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/fr/recherche/cas/tab?customGetLattitude=46.124763699209396&customGetLongitude=2.4169921874999996&customGetZoom=6&field_agregation_index_value=&field_classification_des_cas_target_id=All&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=50.52739681329302&field_latitude_value%5Bmin%5D=41.72213058512578&field_longitude_value%5Bmax%5D=9.8876953125&field_longitude_value%5Bmin%5D=-5.053710937500001&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=118&sort=desc

35. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/fr/recherche/cas?customGetLattitude=43.9503570933062&customGetLongitude=-3.31787109375&customGetZoom=5&field_classification_des_cas_target_id%5B0%5D=11&field_latitude_value%5Bmax%5D=53.014783245859235&field_latitude_value%5Bmin%5D=34.88593094075317&field_longitude_value%5Bmax%5D=8.920898437500002&field_longitude_value%5Bmin%5D=-15.556640625000002&order=title&page=%2C13&sort=desc

36. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/fr/temoignage/7433

37. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=2021-06-26&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=1&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=4%2C1&sort=asc

38. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/en/node/54778

39. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/fr/cas/2010-08-02759

40. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=&field_classification_des_cas_target_id%5B0%5D=12&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_date_d_observation&page=54%2C0&sort=asc

41. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/recherche/cas/tab?customGetLattitude=46.124763699209396&customGetLongitude=2.4169921874999996&customGetZoom=6&field_agregation_index_value=&field_classification_des_cas_target_id=All&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=50.52739681329302&field_latitude_value%5Bmin%5D=41.72213058512578&field_longitude_value%5Bmax%5D=9.8876953125&field_longitude_value%5Bmin%5D=-5.053710937500001&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_date_d_observation&page=140%2C24&sort=desc

42. Source: cnes-geipan.fr
Title: export cas pub 20251127093552.csv
Link:https://www.cnes-geipan.fr/sites/default/files/save_json_import_files/export_cas_pub_20251127093552.csv

43. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/recherche/cas/tab?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=1&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=38&select-category-export=nothing&sort=asc&video=on

44. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/recherche/cas/tab?customGetLattitude=49.42700809484137&customGetLongitude=-0.9608752280473711&customGetZoom=7&field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=51.49757451349519&field_latitude_value%5Bmin%5D=47.35644167618756&field_longitude_value%5Bmax%5D=2.2526257485151295&field_longitude_value%5Bmin%5D=-4.174376204609872&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_date_d_observation&page=2%2C37&sort=desc

45. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/en/recherche/cas/tab?field_agregation_index_value=&field_classification_des_cas_target_id%5B11%5D=11&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=36&sort=desc

46. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_valu_valu=04-23&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_date_d_observation_textuel&page=161%2C0&sort=desc

47. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/recherche/cas/tab?customGetLattitude=46.124763699209396&customGetLongitude=2.406005859375001&customGetZoom=6&field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=50.52739681329302&field_latitude_value%5Bmin%5D=41.72213058512578&field_longitude_value%5Bmax%5D=8.745117187500002&field_longitude_value%5Bmin%5D=-3.9331054687500004&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_classification_des_cas&page=127&sort=desc&undefined=

48. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/fr/recherche/cas/tab?customGetLattitude=46.94358292648825&customGetLongitude=4.4989013671875&customGetZoom=7&field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=49.11702904077932&field_latitude_value%5Bmin%5D=44.77013681219717&field_longitude_value%5Bmax%5D=7.668457031250001&field_longitude_value%5Bmin%5D=1.329345703125&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_date&page=6%2C0&sort=desc

49. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=Photo+&field_is_new_value=All&field_is_revisited_value=All&field_type_de_cas_target_id=All&order=title&page=15&sort=asc

50. Source: cnes-geipan.fr
Title: 2015 09 01 Spatial Point Pattern Analysis of the Unidentified
Link:https://www.cnes-geipan.fr/sites/default/files/2015-09-01_Spatial_Point_Pattern_Analysis_of_the_Unidentified.pdf

51. Source: cnes-geipan.fr
Title: 03 ROSPARS full
Link:https://www.cnes-geipan.fr/sites/default/files/03_ROSPARS_full.pdf

52. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/node/430

53. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/what-did-i-see/step-1

54. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/glossaire

55. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/actualites/evolution-classification-des-cas

56. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/histoire-du-geipan

57. Source: cnes-geipan.fr
Link:https://cnes-geipan.fr/en/search/cas?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=116&order=field_date_d_observation_textuel&page=%2C388&select-category-export=nothing&sort=desc

58. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/en/mentions_legales

59. Source: cnes-geipan.fr
Link:https://www.cnes-geipan.fr/sites/default/files/PV%20n%C2%B0600%20%281990307266%29.pdf

60. Source: ufologie.patrickgross.org
Link:https://ufologie.patrickgross.org/1954/22sep1954saintcheronf.htm

61. Source: cnes.fr
Link:https://cnes.fr/en/projects/geipan

62. Source: videotheque.cnes.fr
Link:https://videotheque.cnes.fr/index.php?id_cat=3105&urlaction=cat

63. Source: insee.fr
Title: Full set of local data − Department of Essonne (91)Essonne (91)
Link:https://www.insee.fr/en/statistiques/6457611?geo=DEP-91

64. Source: insee.fr
Title: Dossier complet − Département de l’Essonne (91)Essonne (91)
Link:https://www.insee.fr/fr/statistiques/2011101?geo=DEP-91

65. Source: insee.fr
Link:https://www.insee.fr/fr/statistiques/1405599?geo=REG-11+DEP-93+DEP-77+DEP-75+DEP-92+DEP-94+DEP-95+DEP-91+DEP-78

66. Source: insee.fr
Link:https://www.insee.fr/fr/statistiques/2011101?geo=EPCI-200056232

67. Source: insee.fr
Title: Population estimates
Link:https://www.insee.fr/en/statistiques/serie/001760181

68. Source: insee.fr
Link:https://www.insee.fr/fr/statistiques/1405599?geo=EPCI-200056232

69. Source: insee.fr
Title: 200056232 communaute paris saclay
Link:https://www.insee.fr/fr/metadonnees/geographie/intercommunalite/200056232-communaute-paris-saclay

70. Source: geipan.fr
Link:https://www.geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=2020-11-18&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=1&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=18&sort=desc

71. Source: geipan.fr
Link:https://geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=&field_classification_des_cas_target_id%5B13%5D=13&field_classification_des_cas_target_id%5B14%5D=14&field_classification_des_cas_target_id%5B15%5D=15&field_classification_des_cas_target_id%5B16%5D=16&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=1&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=57.70414723434193&field_latitude_value%5Bmin%5D=19.642587534013032&field_longitude_value%5Bmax%5D=49.921875&field_longitude_value%5Bmin%5D=-9.843750000000002&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_classification_des_cas&page=12&select-category-export=nothing&sort=desc&video=on

72. Source: geipan.fr
Link:https://geipan.fr/fr/recherche/cas/tab?customGetLattitude=35.188709584047814&customGetLongitude=-33.92578125&customGetZoom=3&field_agregation_index_value=&field_classification_des_cas_target_id%5B11%5D=11&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=70.72897946208789&field_latitude_value%5Bmin%5D=-0.3515602939922709&field_longitude_value%5Bmax%5D=25.839843750000004&field_longitude_value%5Bmin%5D=-93.69140625&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=title&page=4&sort=desc

73. Source: geipan.fr
Link:https://www.geipan.fr/fr/recherche/cas/tab?field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=2021-11-23&field_document_existe_ou_pas_value=All&field_is_new_value=1&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_type_de_cas_target_id=All&order=field_departement_textuel&page=3&sort=asc

74. Source: geipan.fr
Link:https://geipan.fr/fr/recherche/cas/tab?field_date_d_observation_value%5Bmax%5D=&field_date_value=2020-11-18&field_document_existe_ou_pas_value=All&field_is_new_value=1&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_type_de_cas_target_id=All&order=field_date_d_observation&page=20&sort=desc

75. Source: geipan.fr
Link:https://geipan.fr/fr/recherche/cas/tab?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=116&order=field_classification_des_cas&page=36%2C37&select-category-export=nothing&sort=asc