Could Jupiter and Radar Artefacts Explain It?

Introduction

The sceptical case against the JAL 1628 sighting does not rest on a claim that the crew invented the event. Even critics generally accept that Captain Kenju Terauchi and the other crew members sincerely reported unusual lights over Alaska in November 1986. The dispute centres instead on interpretation: whether the encounter involved a structured unknown craft, or a combination of astronomical objects, atmospheric effects, radar ambiguity and expectation-driven misidentification. The most important challenge to the dramatic “mothership” narrative is that independent confirmation remained weak. Nearby aircraft failed to visually confirm the object, later FAA radar reviews concluded that recorded data did not verify unknown traffic, and investigators such as Philip J. Klass argued that Jupiter and other celestial lights offered a more ordinary explanation. [Skeptical Inquirer]skepticalinquirer.orgTerauchi's Marvelous 'Spaceship'Philip J. Klass investigated, and soon CSICOP issued a press release, written by Klass (p. 7):. At the ti… [Wikipedia]WikipediaJapan Air Lines Cargo Flight 1628Japan Air Lines Cargo Flight 1628 [The Black Vault Documents]documents.theblackvault.comThe Black Vault DocumentsUntitledJapan Airlines Flight 1628 on November 18, 1986. Radar data recorded by Anchorage Center does not confir…Published: November 18, 1986

At the same time, the case remains controversial because the sceptical explanations are themselves incomplete. They can account for parts of the sighting more easily than others, but they do not entirely remove the difficulty posed by multiple witnesses, onboard radar reports and the real-time concern shown by air-traffic controllers during the event. That unresolved tension is one reason the incident still occupies a central place in debates over aviation UFO reports.

Why the missing visual confirmation mattered

One of the strongest sceptical points is simple: other aircraft in the area did not see what JAL 1628 claimed to be following it.

During the encounter, Anchorage controllers asked another aircraft, identified in records as a United Airlines flight, to look for the reported object. A nearby US Air Force C-130 was also queried. Neither crew reported seeing unusual traffic either visually or on radar. FAA radar personnel in Fairbanks likewise stated that they observed only the JAL aircraft. [Wikipedia]WikipediaJapan Air Lines Cargo Flight 1628Japan Air Lines Cargo Flight 1628 [Internet Archive]archive.orgInternet ArchiveFAA Japan Air Lines Flight 1628 Records30 Apr 2023 — Anchorage Air Traffic Control obliged and requested an oncoming Unit…

That absence of corroboration matters because Terauchi’s later descriptions became extremely dramatic. He described a huge craft, at times claiming it was larger than an aircraft carrier. Critics argue that an object of that apparent scale, remaining near a Boeing 747 for an extended period, should have been visible to at least some other observers under clear enough conditions for the JAL crew to track lights and apparent structure.

Sceptics also note that the strongest and most elaborate descriptions came primarily from Terauchi himself. The other two crew members gave more restrained accounts. According to later reviews of the FAA interview transcripts, First Officer Takanori Tamefuji described seeing lights but struggled to distinguish them clearly from stars when viewed head-on. [The Debrief]thedebrief.orgwhat really happened to japan airlines flight 1628 in 1986The DebriefWhat Really Happened to Japan Airlines Flight 1628 in…7 Jun 2021 — On November 17th, 1986, Japan Airlines flight 1628 becam…

This does not mean the other crew members saw nothing. It does, however, weaken the claim that all three independently observed a clearly structured craft. Critics argue that the incident evolved from a shared report of unusual lights into a far more elaborate “mothership” narrative largely driven by the captain’s interpretation.

The Jupiter explanation

The best-known sceptical explanation came from aviation writer and UFO critic Philip J. Klass. His argument focused on the night sky conditions over Alaska during the encounter.

Klass noted that Jupiter was exceptionally bright and positioned low on the horizon in the same general direction as the reported lights. Mars was also visible nearby. He argued that under twilight conditions, especially from a high-altitude cockpit with cloud layers and ice haze below, bright planets could appear unusually large, luminous or apparently level with the aircraft. [Wikipedia]WikipediaJapan Air Lines Cargo Flight 1628Japan Air Lines Cargo Flight 1628 [Skeptical Inquirer]skepticalinquirer.orgTerauchi's Marvelous 'Spaceship'Philip J. Klass investigated, and soon CSICOP issued a press release, written by Klass (p. 7):. At the ti…

A key part of the argument involved relative motion illusion. A bright celestial object viewed from a moving aircraft can appear to “pace” the plane because the object remains fixed relative to distant space while nearer terrain and clouds move beneath it. Pilots are trained to avoid this kind of misinterpretation, but it is not unheard of, particularly at night and over featureless terrain.

Klass also stressed that Jupiter’s low elevation could create a false sense that the object occupied the same altitude as the aircraft. He argued that atmospheric scintillation — the same effect that makes stars appear to flicker — combined with thin cloud and ice-crystal layers could produce changing colours and apparent motion. [Skeptical Inquirer]skepticalinquirer.orgTerauchi's Marvelous 'Spaceship'Philip J. Klass investigated, and soon CSICOP issued a press release, written by Klass (p. 7):. At the ti…

The sceptical argument became stronger because some parts of the crew testimony fit astronomical misidentification better than a structured craft. Descriptions of lights changing intensity, disappearing and reappearing, or seeming stationary at times are easier to reconcile with celestial bodies viewed through atmospheric distortion than with a massive nearby vehicle.

However, the Jupiter explanation also has limits. Terauchi and the crew were experienced pilots familiar with night flying, and critics of the sceptical view argue that it is difficult to mistake a planet for a nearby object manoeuvring close to an aircraft over a prolonged period. The debate therefore turns not on whether Jupiter was visible — it clearly was — but on whether that visibility adequately explains the entire sequence of observations.

Ice crystals, clouds and cockpit perception

Atmospheric conditions over Alaska form another major part of the sceptical interpretation.

Investigators pointed to thin cloud layers, reflections and ice-crystal effects as possible contributors to the sighting. High-altitude ice crystals can scatter and refract bright light sources, producing halos, elongated glows, apparent movement and sudden brightness changes. In aviation environments, these effects can become particularly confusing because cockpit windows themselves introduce reflections and layered visual cues.

FAA-linked sceptical commentary later cited another UFO report made by Terauchi in early 1987 that was eventually attributed to village lights diffused through ice-crystal cloud layers. Critics used that later event to argue that the captain may have been unusually susceptible to interpreting ambiguous night lights as structured aerial objects. [Wikipedia]WikipediaJapan Air Lines Cargo Flight 1628Japan Air Lines Cargo Flight 1628

This became controversial because FAA documents reportedly described Terauchi as a “UFO repeater”, noting earlier and later reports from the same pilot. Supporters of the sighting view this label as dismissive and unfair. Sceptics, by contrast, argue that repeated unusual sightings by the same observer can indicate a tendency toward interpretive bias. [Wikipedia]WikipediaJapan Air Lines Cargo Flight 1628Japan Air Lines Cargo Flight 1628

The broader sceptical position is not necessarily that the crew hallucinated or fabricated anything. Instead, it proposes a layered perceptual chain:

Within that framework, a sincere but mistaken report becomes possible without requiring deception.

The radar problem and “double image” explanations

Radar evidence is often presented as the strongest support for the JAL 1628 case, but it is also one of the most disputed aspects.

During the incident, controllers and military personnel discussed intermittent radar returns near the aircraft. At the time, some controllers believed they might be seeing additional traffic associated with the crew’s report. This real-time uncertainty helped make the case famous. [UPI]upi.comRadar review fails to confirm UFOUPIRadar review fails to confirm UFO - UPI Archives8 Jan 1987 — Federal investigators said a review of radar tapes failed to show a UFO s…

Later analysis, however, became far more cautious. FAA review memoranda concluded that Anchorage Center radar data did “not confirm the presence” of the reported traffic. [The Black Vault Documents]documents.theblackvault.comThe Black Vault DocumentsUntitledJapan Airlines Flight 1628 on November 18, 1986. Radar data recorded by Anchorage Center does not confir…Published: November 18, 1986

Subsequent explanations proposed that the apparent secondary radar target may have resulted from radar processing artefacts or “split images” associated with the 747 itself. According to FAA statements reported after the investigation, what initially appeared to be a second object was eventually interpreted as a duplicated or erroneous return rather than an independently tracked craft. [UPI]upi.comController confirms UFO sightingUPIController confirms UFO sighting - UPI Archives30 Dec 1986 — An air controller said radar showed a mysterious object following a Japan…

This distinction is crucial. The existence of ambiguous radar blips is not the same as confirmed tracking of a solid object. Radar systems, especially in difficult coverage regions and under unusual atmospheric conditions, can produce clutter, anomalous returns and temporary false targets.

Sceptics therefore argue that the radar story changed over time in public retellings. Early media reports often framed the event as “radar-confirmed”. The later FAA interpretation was narrower: controllers saw unusual returns temporarily, but investigators concluded that the data did not reliably establish unknown traffic shadowing the aircraft. [UPI]upi.comRadar review fails to confirm UFOUPIRadar review fails to confirm UFO - UPI Archives8 Jan 1987 — Federal investigators said a review of radar tapes failed to show a UFO s… [UPI]upi.comController confirms UFO sightingUPIController confirms UFO sighting - UPI Archives30 Dec 1986 — An air controller said radar showed a mysterious object following a Japan…

Contradictions and memory drift

Another sceptical line of criticism focuses on inconsistencies between early transcripts and later retellings.

Researchers reviewing the FAA files noted discrepancies regarding whether the object remained visible during the aircraft’s 360-degree turn. Some later versions of the story implied the unknown object stayed with the aircraft throughout the manoeuvre. Yet sceptics pointed to radio transcripts suggesting Terauchi at one stage told controllers he had lost sight of it after the turn. [Wikipedia]WikipediaJapan Air Lines Cargo Flight 1628Japan Air Lines Cargo Flight 1628

Differences also appeared in later interviews conducted separately with crew members. Critics argue that memory drift and repeated retelling gradually increased the dramatic elements of the account.

This issue is especially important because the strongest extraordinary claims — enormous size, structured form and intelligent manoeuvring — depended heavily on visual interpretation at night over remote terrain. Once inconsistencies appear in witness recollection, sceptics contend that confidence in those details should decline sharply.

Supporters of the sighting counter that witness inconsistency is normal after stressful events and does not automatically invalidate the entire report. Still, the contradictions weakened claims that the event provided clean, internally consistent evidence of an unknown craft.

What remains unresolved

Despite the sceptical explanations, the JAL 1628 case has never fully disappeared into the category of straightforward misidentification.

Several aspects still resist easy dismissal:

These points prevent the case from fitting neatly into a simple “planet mistaken for UFO” narrative.

At the same time, the strongest evidence for an extraordinary craft remains weaker than popular retellings often suggest. Independent visual confirmation failed. Recorded radar data did not conclusively support unknown traffic. Witness descriptions evolved over time. And several key features of the sighting are compatible with known perceptual and atmospheric effects. [The Black Vault Documents]documents.theblackvault.comThe Black Vault DocumentsUntitledJapan Airlines Flight 1628 on November 18, 1986. Radar data recorded by Anchorage Center does not confir…Published: November 18, 1986 [UPI]upi.comController confirms UFO sightingUPIController confirms UFO sighting - UPI Archives30 Dec 1986 — An air controller said radar showed a mysterious object following a Japan…

That combination — sincere witnesses, ambiguous instrumentation and incomplete corroboration — explains why JAL 1628 continues to divide opinion. For believers, it remains one of aviation’s most compelling UFO encounters. For sceptics, it is a classic example of how extraordinary interpretations can emerge from ordinary lights, imperfect radar and human perception under difficult viewing conditions.

Endnotes

1. Source: Wikipedia
   Title: Japan Air Lines Cargo Flight 1628
   Link: https://en.wikipedia.org/wiki/Japan_Air_Lines_Cargo_Flight_1628

2. Source: upi.com
   Title: Radar review fails to confirm UFO
   Link: https://www.upi.com/Archives/1987/01/08/Radar-review-fails-to-confirm-UFO/8875537080400/
   Source snippet

   UPIRadar review fails to confirm UFO - UPI Archives8 Jan 1987 — Federal investigators said a review of radar tapes failed to show a UFO s...

3. Source: archive.org
   Link: https://archive.org/details/jal1628
   Source snippet

   Internet ArchiveFAA Japan Air Lines Flight 1628 Records30 Apr 2023 — Anchorage Air Traffic Control obliged and requested an oncoming Unit...

4. Source: upi.com
   Title: Controller confirms UFO sighting
   Link: https://www.upi.com/Archives/1986/12/30/Controller-confirms-UFO-sighting/4431536302800/
   Source snippet

   UPIController confirms UFO sighting - UPI Archives30 Dec 1986 — An air controller said radar showed a mysterious object following a Japan...

5. Source: youtube.com
   Link: https://www.youtube.com/watch?v=ekykrn0h7ZE
   Source snippet

   Japan Airlines Flight 1628 - UFO Incident Animation...

6. Source: youtube.com
   Link: https://www.youtube.com/watch?v=DXNfyOVoi7g
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   UFO Sighting at 35,000 Feet | JAL Cargo Flight 1628...

7. Source: documents.theblackvault.com
   Link: https://documents.theblackvault.com/documents/ufos/jal1628/733667-001-012.pdf
   Source snippet

   The Black Vault DocumentsUntitledJapan Airlines Flight 1628 on November 18, 1986. Radar data recorded by Anchorage Center does not confir...

   Published: November 18, 1986

8. Source: skepticalinquirer.org
   Link: https://skepticalinquirer.org/wp-content/uploads/sites/29/2014/11/p19.pdf
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   Terauchi's Marvelous 'Spaceship'Philip J. Klass investigated, and soon CSICOP issued a press release, written by Klass (p. 7):. At the ti...

9. Source: thedebrief.org
   Title: what really happened to japan airlines flight 1628 in 1986
   Link: https://thedebrief.org/what-really-happened-to-japan-airlines-flight-1628-in-1986/
   Source snippet

   The DebriefWhat Really Happened to Japan Airlines Flight 1628 in...7 Jun 2021 — On November 17th, 1986, Japan Airlines flight 1628 becam...

10. Source: documents.theblackvault.com
    Link: https://documents.theblackvault.com/documents/ufos/jal1628/733667-001-003.pdf
    Source snippet

    eek10 Jun 1987 — The FAA has completed its investigation of JAL flight 1628, and does not intend to pursue it any further." II. Page 25...

11. Source: documents.theblackvault.com
    Link: https://documents.theblackvault.com/documents/ufos/jal1628/733667-001-015.pdf
    Source snippet

    theblackvault.comMemorandumINFORMATION: Transcription concerning the incident involving Japan Airlines Flight 1628 on November 18, 1986 a...

    Published: November 18, 1986

Additional References

1. Source: facebook.com
   Title: over alaska pilots have reported something they cant explainstrange lights pacin
   Link: https://www.facebook.com/ChillsDylan/posts/over-alaska-pilots-have-reported-something-they-cant-explainstrange-lights-pacin/869797606149939/
   Source snippet

   Over Alaska, pilots have reported something they can'...Japan Airlines Flight 1628 is one of the most well- documented aviation UFO inci...

2. Source: americanghostwalks.com
   Title: haunted alaskan skies 1986 s japan airlines flight 1628 ufo encounter
   Link: https://www.americanghostwalks.com/haunted-alaskan-skies-1986-s-japan-airlines-flight-1628-ufo-encounter
   Source snippet

   Haunted Alaskan Skies: 1986's JAL1628 UFO Encounter25 May 2025 — There have been many allegations that the testimony of the crew of 1628...

   Published: May 2025

3. Source: reddit.com
   Title: black vault uncovers archives missing faa records
   Link: https://www.reddit.com/r/UFOs/comments/1d2rmv7/black_vault_uncovers_archives_missing_faa_records/
   Source snippet

   Black Vault uncovers, archives missing FAA records...TIL Japan Airlines Flight 1628 over Alaska had a 42 minute long UFO encounter Suppo...

4. Source: reddit.com
   Link: https://www.reddit.com/r/todayilearned/comments/h8o5id/til_japan_airlines_flight_1628_over_alaska_had_a/
   Source snippet

   42 minute...TIL Japan Airlines Flight 1628 over Alaska had a 42 minute long UFO encounter Supported by Radar Data and Air Traffic Contro...

5. Source: flightsafetydetectives.com
   Title: a model for investigating uap events episode 182
   Link: https://flightsafetydetectives.com/a-model-for-investigating-uap-events-episode-182/
   Source snippet

   A Model for Investigating UAP Events – Episode 182JAL Flight 1628 UAP event was investigated in detail by the FAA could serve as a model...

6. Source: researchgate.net
   Link: https://www.researchgate.net/publication/336062892_Estimating_Flight_Characteristics_of_Anomalous_Unidentified_Aerial_Vehicles
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   The UAV and the airplane are approximately to scale, while the distance...

7. Source: reddit.com
   Link: https://www.reddit.com/r/UFOs/comments/1kgy7o7/the_ufo_encounter_so_disturbing_the_cia_buried_it/
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   raffic reported by Flight 1628. No further information has been...

8. Source: magazin.aktualne.cz
   Link: https://magazin.aktualne.cz/jal-1628-boeing-sledovany-ufo-40-minut-nad-aljaskou-nevyrese/r~ff1309b24c4d11f0b589ac1f6b220ee8/v~sl%3A03907859d450270f093a02adf096fd63/
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   1628: Boeing sledovaný UFO 40 minut nad Aljaškou23 Jun 2025 — Nákladní letadlo sledoval gigantický objekt nad Aljaškou celých 40 minut. P...

9. Source: jeromeprophet.blogspot.com
   Title: 1986 jal flight 1628 ufo encounter
   Link: https://jeromeprophet.blogspot.com/2007/02/1986-jal-flight-1628-ufo-encounter.html
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   Jerome ProphetThe 1986 JAL Flight 1628 UFO Encounter!12 Feb 2007 — Radar data recorded by Anchorage Center does not confirm the presence...

10. Source: latimes.com
    Title: la xpm 1987 01 01 mn 1922 story
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    Plane Maneuvered to Avoid Object: Pilot Recounts...1 Jan 1987 — ANCHORAGE — A veteran pilot whose UFO sighting was confirmed on radar s...