🇺🇸 USAF — Project Blue Book
In October 1960, a pilot flying over Japan reported an unusual aerial phenomenon near Misawa Air Base. The object, described as a half-moon the size of half a baseball, appeared with an orange flash that seemed explosive. The pilot observed it for only 1.5 seconds at an altitude of 20,000 feet, with no apparent lateral movement. Due to the object's high elevation (nearly directly overhead), researchers considered it likely to be a meteor whose brightness and shape were hard to interpret from that perspective.
Military investigators concluded it was very probable that the object was a meteor. The lack of lateral movement was explained by the observer's almost direct line of sight, which makes it hard to perceive motion. Although the object's apparent large size raised questions, it was attributed to the normal difficulty in estimating the size of light sources in the sky. There were no other witnesses or evidence of human activity or atmospheric phenomena that could explain the sighting.