NASA's Unexplained Files backdrop
Documentary•Talk•Mystery

The Best Episodes of NASA's Unexplained Files Season 4

Every episode of NASA's Unexplained Files Season 4 ranked from best to worst. Discover the Best Episodes of NASA's Unexplained Files Season 4!

Binge this in 8h 0m•Peaking at 7.3/10

Dive into the mysteries of some of NASA’s most curious missions and explore stories of engineering achievement and human endurance. Each episode offers first hand testimony from astronauts, NASA mission footage, plus beautifully rendered CGI

Airs on
Science
BestEpisodes
WorstEpisodes
BestSeasons
AllEpisodes

Seasons6

All123456

Episode Rankings

  1. #1 Fan Favorite
    NASA's Unexplained Files Season 4 Episode 8 - Mars's Deepest Secret
    7.3/10(27 votes)

    S4:E8

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

  2. NASA's Unexplained Files Season 4 Episode 3 - A President's Close Encounter
    7.2/10(28 votes)

    S4:E3

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

  3. NASA's Unexplained Files Season 4 Episode 6 - Did Earth Have Two Moons?
    7.2/10(31 votes)

    S4:E6

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

  4. NASA's Unexplained Files Season 4 Episode 7 - Mystery of the Invisible Planet
    7.1/10(27 votes)

    S4:E7

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

  5. NASA's Unexplained Files Season 4 Episode 4 - The Earth Next Door
    7.0/10(28 votes)

    S4:E4

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

  6. NASA's Unexplained Files Season 4 Episode 2 - Rise of the Planet Killer
    6.9/10(30 votes)

    S4:E2

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

    7. Trending NowTRENDING NOW

    The 20 BEST Episodes of NASA's Unexplained Files

    READ
  7. NASA's Unexplained Files Season 4 Episode 1 - Pluto's Stranger Things
    6.7/10(28 votes)

    S4:E1

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

  8. NASA's Unexplained Files Season 4 Episode 5 - Curse of the Full Moon
    6.6/10(25 votes)

    S4:E5

    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.

    Director:Unknown
    Writer:Unknown

    Be the first to start the conversation for this episode

Season 4 Ratings Summary

"Mars's Deepest Secret" is the best rated episode of "NASA's Unexplained Files" season 4. It scored 7.3/10 based on 27 votes. Directed by Unknown and written by Unknown, it aired on 10/18/2016. This episode is rated 0.1 points higher than the second-best, "A President's Close Encounter".