Disc / Saucer

The discoid morphology dominated UAP reports from the 1947 Arnold sighting through the 1960s. Continues to be reported worldwide; less prevalent in modern military encounter logs.

The disc is the form that named the phenomenon. In June 1947 the aviator Kenneth Arnold described nine objects moving near Mount Rainier as skipping “like a saucer would if you skipped it across water” — a remark about motion that the press rendered as “flying saucer,” and the shape stuck. For the better part of two decades afterwards the discoid morphology, often with a domed upper section, dominated the popular and investigative record alike, defining the post-war era of sightings.

Its prevalence makes the disc both well-attested and heavily contaminated. The form correlates strongly with the 1947-1960s wave and with mid-century civilian reports worldwide, but it is also the shape most freely borrowed by hoaxes, misidentified lenticular clouds, and out-of-focus lights. Many classic disc photographs have been resolved as fakes or mundane objects, which places much of the corpus toward the lower end of our evidential hierarchy.

Notably, the disc is comparatively scarce in modern military encounter logs, where spheres, ovoids and the Tic-Tac form recur instead. That shift — a once-dominant shape now seldom radar-confirmed — is itself part of the file, and we treat the legacy discs case by case rather than as a class.