Unusual mushroom-shaped cloud seen in Alaska

Summary

A civilian pilot in Alaska observed an unusual cloud formation resembling a mushroom rising from the horizon. The sighting occurred on September 15, 1961, when the pilot, flying at 6,500 feet, saw a formation extending three degrees above the horizon. The cloud remained stationary for 20 minutes, and the pilot estimated it was 300-400 miles away. Weather conditions were clear with excellent visibility, ruling out other objects in the area.

The official evaluation concluded it was an astronomical phenomenon, identified as Venus. This was not the pilot's first such sighting, as a similar event had previously been reported and also classified as Venus. Despite the unusual appearance, it was not considered a threat, and no further information was recorded. The report was shared with several military and intelligence agencies, but no definitive conclusion about the object's nature was reached.