Where Did They Come From?
There were some clues that the balloons were Japanese in origin – such as the markings on the altimeter — but the U.S. military wasn’t entirely sure where they came from.
Perhaps they were launched from the internment camps in California? Or were they from Japanese submarines? They were able to pinpoint the exact location when they tested the sand from a sandbag still attached to the balloon. The sand was unique to the Japanese mainland, making it clear who was responsible. But what was the purpose, and how did they get here?