Kaikōura: a film and two technical readings

The 25 January 1979 memorandum — Archives New Zealand; Ministry of Foreign Affairs and Trade. Resized only.
Document scan. Complete memorandum page, resized from Archives New Zealand’s published scan. It reports an investigation still in progress. Archive reference ABHS 6958 W5579 Box 227 NYP 3/58/13 Part 1.
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A television crew filmed lights from a freight aircraft. The technical dispute concerns what the film and radar ranges can actually be made to measure.

World: Earth
Location: New Zealand
Case date or period: 30–31 December 1978

Separate nights and separate lights

The Kaikōura story includes several observations during December 1978, not one uninterrupted encounter. A television crew joined a freight flight on 30–31 December after earlier reports had drawn attention to the area. Cameraman David Crockett filmed bright lights from the Argosy piloted by Bill Startup. The best-known technical argument concerns a particularly bright light seen on the return leg after leaving Christchurch in the early morning. Conclusions about that sequence cannot automatically be applied to every earlier visual or radar report associated with the wider episode.

Maccabee measures the film

Optical physicist Bruce Maccabee published a photometric analysis in Applied Optics in 1979. He used film-density measurements, camera information and reported airborne-radar ranges to estimate the source’s light output. His paper explicitly notes a limitation: individual film segments were not precisely timed, so exact ranges could not be assigned to specific frames. Much of the imagery was smeared by handheld camera motion or heavily overexposed. These are not incidental flaws. They determine how far a bright recorded patch can support a calculation of an actual source’s brightness and position.

Ireland challenges the assumed source

Bill Ireland, who had worked on the official scientific assessment, argued that a squid-fishing vessel or group of vessels could explain the bright return-flight light. In his later review, he emphasized that the aircraft radar was operating in a ground-mapping mode and could detect something below the aircraft. He also examined the spacing and arrangement of lights in a film copy. This addressed an ordinary source that could be both bright and radar-reflective. His proposal concerned a particular filmed sequence; it was not a demonstrated explanation for every report made during the December sightings.

What officials said at the time

A 25 January 1979 memorandum preserved by Archives New Zealand describes the investigation as continuing without definite results. It records work on anomalous radar returns, film distortion and possible atmospheric effects. It also relays claims about reproducing visual distortions through an aircraft window and cautions that reported ground-radar signals did not coincide with all pilot or ground sightings. This is an authentic contemporary account of the official position, not a later editorial summary. Its provisional wording matters: the memorandum’s scepticism about an extraordinary interpretation was not presented as a completed identification of every light.

Why a bright image is not a distance

The disagreement turns partly on linking the visible light to the radar return and then using that range in an optical calculation. If the association or range is wrong, the inferred luminosity changes. A luminous patch’s shape is also affected by focus, exposure, motion and the window through which it was filmed. Maccabee’s published measurements made those questions concrete enough to debate. The debate does not disappear because the paper appeared in a scientific journal, and an ordinary candidate source still needs to fit the relevant timing, direction and optical circumstances.

The evidence available in this case

The local image is the complete government memorandum page preserved by Archives New Zealand: an investigation document, not an object photograph. The publisher’s player also presents Paul Davidson’s edited retrospective, combining historical film extracts, later interviews, narration and illustrations. It is not an uninterrupted 1978 camera original. The source list leads to Maccabee’s optical paper and Ireland’s technical criticism. These materials preserve different parts of the investigation; their availability does not turn uncertain frame timing or radar associations into measured facts. Read them as competing interpretations of particular observations, keeping the separate December nights and the memorandum’s provisional wording visible.

The film copy behind the later reassessment

Ireland’s 2000 assessment used a video recording of the BBC’s 1982 Horizon documentary, which contained selected Crockett film. He said the copy had been overlooked in his possession since 1983. That provenance matters when comparing his later reading with Maccabee’s access to the film in 1979: they were not examining identical presentations under identical conditions. The journal record also preserves Ireland and M. K. Andrews’s December 1979 comments and Maccabee’s June 1980 reply. Applied Optics closed the exchange because it had moved beyond the journal’s technical scope. That editorial decision was not an identification of the light.