On the evening of August 23, 1974, John Lennon was in his New York City apartment when he saw what he described as a UFO — a glowing, red, oval-shaped object hovering outside his window.

This case matters because it is a documented encounter event whose object identity remains unresolved.
Documented
On the evening of August 23, 1974, John Lennon was in his New York City apartment when he saw what he described as a UFO — a glowing, red, oval-shaped object hovering outside his window.
Debated
The identity of the object
Debated
The adequacy of the conventional explanation
Unverified
Extraterrestrial origin
Unverified
Any claim stronger than the record supports
Sources are kept in separate layers: official and contemporary material is documented; secondary UFO literature is treated as debated, not as primary evidence.
Secondary / debated material.
Secondary / debated material.
Secondary / debated material.
Secondary / debated material.