Types of UFOs

The round, domed disc that named the whole subject in 1947.

The disc is the original and still the default. A reporter's paraphrase of Kenneth Arnold's 1947 description, that his nine objects moved 'like a saucer skipped across water', gave the world 'flying saucer', and the shape stuck even though Arnold's objects were crescents. Classic discs are smooth, metallic, domed on top, sometimes with portholes or a ring of lights, and they hover, tilt to move, and leave silently.

Discs dominated reports from 1947 into the 1970s and remain the icon of the subject on every poster and toy shelf. The Adamski 'scout craft', a bell with three spheres beneath, is a famous sub-type from the contactee era.

Usually turns out to be Weather balloons, lenticular clouds, and reflective aircraft account for many daylight discs; the shape also spread through film and press imagery, so later witnesses reproduced it.

A large, silent, dark triangle with a light at each corner.

From the late 1980s the disc gave way to the triangle. Witnesses describe a huge, flat, matte-black craft, often estimated at hundreds of feet, gliding slowly and silently with a white light at each corner and sometimes a red light at the centre. The Belgian wave of 1989–1990 and the Phoenix Lights of 1997 are the defining cases.

The triangle is the shape of the modern era, and its rise tracks a real technological change: the F-117 and B-2 stealth aircraft entered service in exactly those years.

Usually turns out to be Stealth aircraft, formations of conventional planes with navigation lights, and blimps explain most triangles; a single dark shape blotting stars between three lights can be one aircraft seen from below.

A long, wingless cylinder, sometimes called a mothership.

The cigar is a long, seamless tube with no wings or tail, hanging horizontally or hovering nose-up. Some accounts describe smaller discs entering or leaving it, which is where the word 'mothership' comes from. Cigars featured heavily in 1950s European waves and in the airship 'sightings' of 1896–97 that preceded the saucer era.

Usually turns out to be Airships and blimps, contrails lit at sunset, and re-entering rocket bodies produce long luminous tubes; the 1896 airship wave coincided with real dirigible development in the press.

A glowing ball of light, the most common shape in modern reports.

A simple ball of light, white, orange, red or shifting, is now the most frequently reported object of all. Orbs range from the 'foo fighters' that paced Second World War aircraft to the glowing sphere of the Allagash case to the countless lights filmed on phones today. They have no visible structure, which is exactly why they overlap with so many ordinary sources.

Usually turns out to be Lanterns, drones, flares, planets, satellites and ball lightning all present as orbs; in photographs, dust or insects lit by a flash produce them.

A smooth white oblong with no wings, rotors or exhaust.

Named for its shape by the Navy pilots who chased one off California in 2004, the Tic Tac is a featureless white capsule about forty feet long, with no wings, control surfaces or visible propulsion. It became the emblem of the modern UAP era after the Nimitz video and testimony went public in 2017.

Usually turns out to be Analysts have proposed distant aircraft, balloons and infrared-camera artefacts; the close-range visual account by trained aviators is the part that resists an easy answer.

A V or chevron of lights moving as one, sometimes a solid wing.

A shallow V or boomerang, either a formation of lights or a single vast wing, crosses the sky slowly and silently. The Hudson Valley sightings of the 1980s and the first phase of the 1997 Phoenix Lights are the classic examples. Witnesses often disagree about whether they saw many lights or one connected object.

Usually turns out to be Formations of light aircraft or microlights flying in a V, and flocks of birds catching ground light, produce boomerangs; the 'solid wing' is usually inferred, not seen.

A rounded, legged craft the size of a car, reported at landings.

Close-encounter landing cases favour a small egg- or bell-shaped object, often on legs, roughly the size of a car. Socorro in 1964, Valensole in 1965 and the Villas Boas case of 1957 all describe this form, sometimes with a central column or a lit doorway. It is the shape most associated with occupants and ground traces.

Usually turns out to be Landing cases are hard to test because they rest on few witnesses; a hoax, a misidentified vehicle or a genuine unexplained event are all argued for the strongest of them, such as Socorro.

An angular diamond or lozenge, occasionally with flame beneath.

Less common but distinct, the diamond appears in cases such as Cash-Landrum in 1980, where witnesses reported a diamond-shaped object venting flame and escorted by helicopters. The shape blurs into the triangle at a distance and is often tied to claims of a secret military craft.

Usually turns out to be Where a diamond is tied to helicopters, as at Cash-Landrum, a classified aircraft test is the witnesses' own theory; no such craft has ever been confirmed.

The odd shapes of the crash-retrieval stories: acorns, discs, debris.

Crash cases have their own iconography: the bronze acorn said to have landed at Kecksburg in 1965, the disc of Roswell, the object that floated and sank at Shag Harbour. These are shapes described after the fact, often by few witnesses, and they anchor the recovery mythology more than the sighting record.

Usually turns out to be Meteors, re-entering satellites and balloon trains account for the falls; the recovered-craft claims rest on later testimony and disputed documents.