Season 4 Episode Guide

Mars's Deepest Secret

Season 4, Episode 8

October 18, 2016

Mystery of the Invisible Planet

Season 4, Episode 7

October 11, 2016

Did Earth Have Two Moons?

Season 4, Episode 6

October 4, 2016

Curse of the Full Moon

Season 4, Episode 5

September 27, 2016

The Earth Next Door

Season 4, Episode 4

September 20, 2016

A President's Close Encounter

Season 4, Episode 3

September 13, 2016

Rise of the Planet Killer

Season 4, Episode 2

September 6, 2016

Pluto's Stranger Things

Season 4, Episode 1

August 30, 2016

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  • Premiered: March 2, 2014
  • Rating: TV-PG
  • Premise: Purported UFO sightings by astronauts and questionable images captured by NASA's cameras are discussed. (more)

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