When a mysterious crescent appeared over Moscow in 1967, alien enthusiasts were unaware they were actually tracking a 3-megaton weapon designed to bypass American radar.
Explore the disappearance of 3.8 million declassified UFO files from The Black Vault after Trump's transparency order.
Documents might help scientists shed light on unexplained phenomena and government secrets, experts said.
Were two Ohio fishermen abducted by aliens? The still unexplained encounter happened at Salt Fork State Park in Guernsey ...