The Black Knight satellite
The account
A 13,000-year-old alien satellite is said to orbit Earth, watching humanity, and a NASA photo would be the proof.
What investigators found
The 1998 photo shows a thermal blanket that came loose during a spacewalk. The legend stitches together separate episodes that have nothing to do with one another.
The story
The Black Knight legend combines several stories: radio signals picked up by Nikola Tesla in 1899, newspaper reports from the 1950s about mysterious satellites, and a dark object detected in orbit in 1960, probably a piece of an American military satellite.
The most famous piece is a 1998 photo, taken on the space shuttle mission that began assembling the International Space Station. It shows a dark, twisted object against the Earth. NASA explained that it was a thermal blanket lost by astronauts during a spacewalk. The legend remains popular, but none of its pieces holds up to scrutiny.