First I should report that this is a 3rd hand report. My father told me about an incident which occurred while he was a Sergeant in the Air Force. At the time he was the driver for a Colonel at the base in Cheyenne. My dad always told me to take this story with a grain of salt.
One day the Colonel, whom my dad never named, came back to the vehicle roaring drunk. He then told my dad a story he never knew whether to believe or not.
The colonel had gone to a UFO crash site. Apparently he said that radar had tracked something that had come from the vicinity of Venus. When it hit the atmosphere, it did so at speed. There was a hole in the craft about 6" in diameter, and the insides were burned by reentry heat. Speculation was that it had been hit by a meteoroid sometime during the trip. Three bodies were found, charred beyond recognition. Pieces of the craft were everywhere, including a metal sphere with a peculiar characteristic. When spun, even by hand, it became extremely difficult to move it.
My dad couldn't tell me if that meant move as in gyroscopic motion or an inability to take it from place to place while in motion.
He told me the story because of my interest in antigravity, so if there were other details, I was never told.