Project 10073 Record Card — Montreal, Canada, November 1951

This document contains a sighting report and subsequent technical analysis regarding an unidentified aerial phenomenon observed in Montreal, Canada, in November 1951. The primary witness, an amateur astronomer, reported seeing a large, ring-shaped object at approximately 11:00 p.m. near the intersection of Decary Boulevard and Sherbrooke Street. The witness provided a detailed, albeit highly speculative, account of the object's appearance, claiming it changed colors from green to mauve and then to an orange-red halo. The witness attempted to perform complex mathematical triangulations to estimate the object's size, altitude, and speed, concluding that the object was a 'SPHEREANNO' plane, a term he coined, which he speculated might be a secret German or Soviet invention. The report includes several hand-drawn diagrams and maps attempting to reconstruct the flight path and the observer's line of sight. Despite the witness's elaborate technical claims, the official Project 10073 record card, which serves as the cover for the file, categorizes the event as a probable meteor. The document reflects the intersection of civilian reporting and military intelligence evaluation during the early years of the U.S. Air Force's UFO investigation projects. The file includes multiple enclosures, including technical drawings and reports, all marked with the reference number AF-473351. The witness expressed regret that no other witnesses were present to corroborate his account, specifically noting that a bus driver at the scene might have seen the object but could not be located. The document provides a clear example of how individual observers often attempted to apply scientific rigor to their sightings, while official military evaluators frequently dismissed such reports as natural phenomena like meteors.