Baltimore, MarylandFebruary 1955

A large, bubbly mass fell from the sky over Baltimore on February 23, 1955, and was watched by at least 25 people as it slowly disintegrated on the ground. The object resembled something between soap suds and fish eggs, had great elasticity, and released a smoke similar to steam. When children poked it with sticks and a bystander struck it with a pencil, neither the stick nor pencil showed any residue, suggesting the mass was not solid.

The object had landed on a parked car before sliding to the pavement, leaving only a pale yellowish stain. The Air Force collected samples and forwarded them to the Air Technical Intelligence Center (the branch responsible for analyzing unusual aircraft observations) for chemical analysis. Investigators identified several possible sources: industrial operations in the nearby Westport area used a cleaning compound called Peraag (containing oxalic acid, sodium bisulfate, and a wetting agent) to wash railroad cars under high pressure. A chemist working for the Baltimore and Ohio Railroad later confirmed that this compound could foam and bubble when agitated, turning white and leaving a pale yellow residue. While investigators could not definitively identify the object, they suggested analysts look for oxalic acid, sodium, or sulfate as likely components.

The Air Force's official evaluation for this case was unidentified, though the file suggests the most probable explanation was industrial foam or cleaning compound from the Westport industrial area. The complete case file, consisting of 22 pages held by the National Archives, is reproduced below.