4 - 1The Time Travel Enigma May. 15, 2018- 4 - 2Mission to the Red Planet May. 22, 2018
- 4 - 3Hunt for the Edge of the Universe May. 29, 2018
- 4 - 4Journey to Alien Earths Jun. 05, 2018
- 4 - 5Wrath of the Black Hole Jun. 12, 2018
- 4 - 6New Race to the Moon Jun. 19, 2018
- 4 - 7Mars: The Next Frontier Jun. 26, 2018
- 4 - 8Secret History of the Juno Mission Jul. 10, 2018
- 4 - 9Mystery of the Northern Lights Jul. 17, 2018
- 4 - 10Pluto's Strange Secrets Oct. 14, 2018
