NASA's Unexplained Files
Season 4
20168 episodes
Episode 1
Pluto's Stranger Things
Aug 30, 20161h
Astronomers find evidence for incredible alien technology around a distant star. The first pictures of Pluto may show something moving across its surface. Apollo astronauts see something they can't explain as they approach the Moon.
Episode 2
Rise of the Planet Killer
Sep 6, 20161h
A probe captures an image of a strange structure on Mars. Files from the first Apollo mission record an eerie sighting on the dark side of the Moon. A planet-eating star gives scientists a glimpse of Earth's terrible demise.
Episode 3
A President's Close Encounter
Sep 13, 20161h
Geysers are discovered on a frozen moon, and NASA redirects a probe on a daring mission to detect evidence of life. An unidentified object is spotted approaching a near-earth asteroid. A future president is an eyewitness to a UFO.
Episode 4
The Earth Next Door
Sep 20, 20161h
Astronomers detect a potentially habitable planet tantalizingly close to Earth. A chance discovery at NASA reveals a top secret military space program. The Apollo missions bring back evidence that the moon may be rich in the building blocks for life.
Episode 5
Curse of the Full Moon
Sep 27, 20161h
Two cosmonauts fight for their lives while trapped inside a capsule in a frozen lake. A NASA scientist investigates the deadly Nazi secret that doomed the Hindenburg. NASA astronomers are spooked when the full moon starts affecting their experiments.
Episode 6
Did Earth Have Two Moons?
Oct 4, 20161h
A discovery suggests the hellish clouds of Venus may be the origin of life on Earth. A bizarre sighting 2,000 years ago raises the possibility that Earth once had two moons. A scientist helps the FBI crack the 1996 Olympic bombing.
Episode 7
Mystery of the Invisible Planet
Oct 11, 20161h
A probe carrying a message to aliens malfunctions as it enters deep space. A NASA mission goes disastrously wrong when an imposter breaches Mission Control. Astronomers may have found an invisible planet around a distant star.
Episode 8
Mars's Deepest Secret
Oct 18, 20161h
British astronomers working for the CIA intercept Soviet photos of the moon. A malfunction on the ISS could poison its crew with ammonia gas. A startling image taken by a NASA probe points to evidence that life could exist on Mars.