NASA's Unexplained Files

Strange flying objects have been caught on NASA’s cameras and astronauts have reported seeing UFOs. Some can be identified; others remain a mystery. We’ll reveal NASA footage and interview the astronauts and scientists.

Astronaut Leroy Chao’s spacewalk is interrupted by bright lights flying past. A flying saucer photographed from the Apollo capsule, dark shapes caught on camera shadowing the shuttle. The ideas are science fiction, but the incidents are science fact.

The Viking Lander may have found life on Mars, so why don’t we know about it? What is the most destructive force in the universe? How could a starship be seen in the Aurora Borealis? And what are NASA’s mysterious Moon Pigeons?