NASA's Unexplained Files (2012–present)

1. S01E01PilotMarch 27, 2012—Strange flying objects have been caught on NASA’s cameras and astronauts have reported seeing UFOs. Some can be identified; others remain a
2. S01E02Shadow DeathstarMarch 2, 2014—Astronaut Leroy Chao’s spacewalk is interrupted by bright lights flying past. A flying saucer photographed from the Apollo capsule, dark sha
3. S01E03Alien Death RayMarch 6, 2014—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 coul
4. S01E04Black Knight RisesMarch 11, 2014—A chunk of the sun appears to have vanished. An ominous dark craft beneath the Space Shuttle Endeavour. Hubble spots thousands of unidentifi
5. S01E05Interstellar Gold RushMarch 18, 2014—A distant planet shows evidence of an Earth-like atmosphere, while a mysterious light suggests an atmosphere on the Moon. Have we found evid
6. S01E06Ghosts on the MoonJuly 20, 2014—Could spaceships be powered by atomic bombs? Can artificial rings encircle an entire star? why was Neil Armstrong’s transmission feed cut o
7. S01E07Mystery Space SquidJuly 24, 2014—What could make a NASA astronaut report seeing a flying saucer in the skies above a US Air Force test range? How have the swirling gases of

Season 1 ranked & reviewed

1. S02E01Life in HellMarch 2, 2015—A UFO crashes in Pennsylvania. Was it a secret Soviet satellite or something far more dangerous? On Mercury, NASA finds the impossible: froz
2. S02E02Top Secret TerrorMarch 4, 2015—Was the Moon landing faked? Images of Mercury reveal massive spider-like formations on its surface. Is it a geological formation or somethin
3. S02E03Hammer of ThorApril 22, 2015—Are burning lights above Nevada and Utah signs of a secret space weapons project? What are the odd trails on the lunar surface near the Apol
4. S02E04Spacewalk of DoomApril 29, 2015—How could an astronaut on a spacewalk begin to drown? Have NASA scientists discovered an asteroid that was converted into a spacecraft? What
5. S02E05Did We Nuke Jupiter?May 6, 2015—Could NASA be responsible for a nuclear explosion on Jupiter? Could new evidence finally solve the mystery of the iconic face on Mars? What
6. S02E06Nazis on the MoonMay 13, 2015—A Russian probe discovers the lunar soil was disturbed before the US or USSR got there. Did Nazis arrive first? Have scientists detected a l
7. S02E07Lethal WeaponsMay 20, 2015—How did pictures from the Hubble telescope make the comet of the century look like an alien spacecraft? Has earth already been invaded by al
8. S02E08Revenge of the FirefliesMay 27, 2015—Something in space is attacking the brains of astronauts. What is it? Should NASA be worried about the sudden appearance of so-called space

Season 2 ranked & reviewed

1. S03E01Pluto Under PressureFebruary 23, 2016—Lost tapes reveal that Apollo astronauts heard unexplained transmissions on the far side of the moon, an amateur astronomer spots a strange
2. S03E02Return of the Moon BugsMarch 1, 2016—Apollo 12 astronauts bring back something alive from the moon and NASA track an asteroid heading towards Earth but make a shocking discovery
3. S03E03Rise of the Ice CreaturesMarch 8, 2016—Neil Armstrong goes into an unexplained spin. He needs to figure out what’s causing it, or he faces certain death. An Apollo 17 photo seems
4. S03E04Ghosts on a CometMarch 15, 2016—When a Chinese moon rover breaks down, a NASA scientist points to a mysterious material that seemed to sabotage the Apollo missions, decades
5. S03E05The Moon that DisappearedMarch 22, 2016—Recently discovered documents reveal NASA's secret plan B for failure of the first moon landing, a Soyuz capsule carrying astronaut Peggy Wh
6. S03E06Curse of the Red PlanetMarch 29, 2016—Three cosmonauts die mysteriously as they re-enter Earth's atmosphere. A declassified document reveals a CIA plan to use a space disaster as
7. S03E07Red Storm RisingApril 5, 2016—Two astronauts trapped in the vacuum of space face an agonizing death; the first close up images of Pluto reveal an alien landscape, and res
8. S03E08Attack of the ThunderballsApril 12, 2016—Astronauts are evacuated when a mystery object is discovered hurtling towards the ISS, a NASA secret agent goes undercover to recover missin

Season 3 ranked & reviewed

1. S04E01Pluto's Stranger ThingsAugust 30, 2016—Astronomers find evidence for incredible alien technology around a distant star. The first pictures of Pluto may show something moving acros
2. S04E02Rise of the Planet KillerSeptember 6, 2016—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 t
3. S04E03A President's Close EncounterSeptember 13, 2016—Geysers are discovered on a frozen moon, and NASA redirects a probe on a daring mission to detect evidence of life. An unidentified object i
4. S04E04The Earth Next DoorSeptember 20, 2016—Astronomers detect a potentially habitable planet tantalizingly close to Earth. A chance discovery at NASA reveals a top secret military spa
5. S04E05Curse of the Full MoonSeptember 27, 2016—Two cosmonauts fight for their lives while trapped inside a capsule in a frozen lake. A NASA scientist investigates the deadly Nazi secret t
6. S04E06Did Earth Have Two Moons?October 4, 2016—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 possibili
7. S04E07Mystery of the Invisible PlanetOctober 11, 2016—A probe carrying a message to aliens malfunctions as it enters deep space. A NASA mission goes disastrously wrong when an imposter breaches
8. S04E08Mars's Deepest SecretOctober 18, 2016—British astronomers working for the CIA intercept Soviet photos of the moon. A malfunction on the ISS could poison its crew with ammonia gas

Season 4 ranked & reviewed

1. S05E01JFK UFO ConspiracyApril 12, 2017—A declassified letter written by President Kennedy demands the CIA share its UFO data with NASA. A bizarre pattern on the surface of Mars co
2. S05E02Curse of the Gas GiantApril 19, 2017—Jupiter is far hotter than it should be, and scientists don't understand why. The Curiosity Rover finds something strange on Mars. Could it
3. S05E03The Sun's Evil TwinJanuary 6, 2018—Two suns are photographed in the Indonesia sky -- a trick of the light or a sighting of our Sun's evil twin? Scientists are baffled by ghost
4. S05E04Secret AliensJanuary 13, 2018—An astronomer records an unusual signal from a distant star. FBI agents find classified documents at the home of a NASA scientist. When scie
5. S05E05Stonehenge on MarsJanuary 20, 2018—When NASA spots a something on Mars that resembles Stonehenge, they investigate what could have made this strange structure. Scientists disc
6. S05E06CIA's Secret RevengeJanuary 27, 2018—When the Soviet Union unveils its own space shuttle, the CIA hatches a secret revenge plot. Recent discoveries shed new light on the destruc
7. S05E07The Moon's Strange SecretFebruary 3, 2018—The last humans to walk on the Moon discover something strange on the surface. A NASA scientist investigates a strange phenomenon responsibl
8. S05E08Saturn's Death StarFebruary 10, 2018—A mysterious object is orbiting Saturn, and it looks just like the Death Star. New evidence might shed new light on the mysterious death of

Season 5 ranked & reviewed

1. S06E01Saturn's Moon MonstersApril 11, 2019—When NASA discovers something strange on Saturn's biggest moon, experts investigate if aliens feeding on the electric atmosphere could be th
2. S06E02Aliens vs. Stalin at Area 51April 18, 2019—When a former Area 51 insider alleges that the Roswell UFO incident was a nefarious Soviet conspiracy masterminded by Stalin, experts invest
3. S06E03The Black Hole Next DoorApril 25, 2019—When astronomers discover a rogue black hole speeding through the Milky Way, they investigate how much danger this cosmic monster poses to E
4. S06E04Pluto's Evil TwinMay 2, 2019—After NASA's New Horizons spacecraft flies by Pluto, it encounters a strange alien world that shuts down the probe's computers, and experts
5. S06E05Aliens in the AmazonMay 9, 2019—After Neil Armstrong's moonwalk, he led an expedition to the Amazon to find a legendary library that holds all knowledge of an advanced alie
6. S06E06Secrets of the Alien SignalsMay 16, 2019—When NASA begins a strange experiment to communicate with dolphins, experts investigate if it's a prelude to making alien contact. But some
7. S06E07Planet of the Metal AliensMay 16, 2019—Experts investigate if a nearby exoplanet could be the home to a alien civilization of strange, metallic monsters, after a new discovery con
8. S06E08Did Aliens Nuke Mars?May 23, 2019—A strange discovery by NASA's Mars Curiosity rover suggests the Red Planet was home to an alien nuclear war 300 million years ago. Experts i

Season 6 ranked & reviewed