Director: Ian Levison
A look is taken at exclusive NASA footage and firsthand accounts of mysterious fly objects from astronauts and scientists are presented.
A UFO crashes in Pennsylvania. Was it a secret Soviet satellite, or something far more dangerous? On Mercury, NASA finds the impossible: frozen water.
Images of Mercury reveal massive spider-like formations on its surface. Is it an odd geological formation - or something much more ominous?
The show returns with more mysterious encounters, unusual discoveries and strange sightings, straight from NASA's best and brightest.
Two cosmonauts fight for their lives, trapped inside a capsule in a frozen lake. NASA astronomers are spooked when the full moon affects their experiments.
A starling discovery suggests the hellish clouds of Venus may be the origin of life on Earth. Plus, did the earth once have two moons?