On the morning of December 1, 1987, a person later publicly identified by the pseudonym Philip Spencer was walking across Ilkley Moor in West Yorkshire. Spencer had brought a camera and a compass while crossing the moor in foggy conditions. According to the account later published by investigators, Spencer noticed an unusual figure ahead on the path.

Spencer described the figure as small, with an unusually large head and long, thin limbs. Spencer said the figure appeared to gesture before Spencer took a single photograph. The figure then moved away and disappeared into the fog.

The photograph became the central physical artifact associated with the case. It shows a distant dark figure against the moorland landscape, but the image contains too little detail to identify the subject reliably. Conventional interpretations have included an ordinary person or a deliberately positioned cut-out, while UFO researchers have argued that the figure's proportions appeared unusual. The photograph itself cannot establish the subject's height or distance from the camera without independently verified information about precisely where the subject stood.

Spencer said the encounter did not end with the photograph. After following the figure through the fog, Spencer reported seeing a whitish unidentified craft rise from the moor and disappear into the sky. No photograph of that reported craft was obtained.

Spencer later reported another unusual element: a substantial discrepancy between the amount of time expected for the journey and the time actually shown on arrival. Spencer also said the compass carried across the moor appeared to point incorrectly. These details subsequently became important to investigators, but they depend upon Spencer's account rather than an independently preserved instrument record.

In the days following the reported incident, Spencer contacted UFO investigators Jenny Randles and Peter Hough. Their investigation and later publication became the principal route through which the case entered UFO literature. This creates an important evidentiary distinction: much of what is known about Ilkley Moor comes through the investigators' presentation of one witness's experience rather than through contemporary police, military, medical, or independent eyewitness records.

Various analyses of the photograph have subsequently been reported. Supporters have argued that examination showed the photographed figure was present in the original image rather than being added later. Even if accepted, that conclusion addresses photographic manipulation rather than the identity of the subject. A genuine photograph of an unidentified figure is not, by itself, evidence that the figure was non-human.

This distinction is especially important because a more elaborate account developed later. Several months after the original report, hypnosis was used in an attempt to explore Spencer's reported period of missing time. The resulting narrative introduced a claimed abduction experience and additional details that were not part of the immediate photographic record. Hypnotically recovered material should therefore be kept separate from what Spencer consciously reported closer to the alleged encounter.

The surviving evidence also has significant archival limitations. A recent source-led review notes that the original negative and complete laboratory analysis report are not publicly available. That restricts the ability of later researchers to repeat earlier photographic analyses or independently evaluate precisely what testing was performed.

The Ilkley Moor case is therefore narrower than later “alien abduction” descriptions sometimes suggest. One witness reported seeing and photographing an unusual figure, later reported seeing an unidentified craft, and described unexplained missing time and compass behavior. A photograph associated with the account survives, but its subject cannot be identified from the available image.