S05E02: Mystery of Planet 9
Scientists have discovered a mysterious ninth planet on the very edge of our solar system. Ten times the size of Earth, this strange world could have moons with extraterrestrial life.
Previous Episode 
Season 1
Big Bang
S1E1 / 25 Apr 2010
Black Holes
S1E2 / 02 May 2010
Galaxies
S1E3 / 10 May 2010
Stars
S1E4 / 10 May 2010
Supernovas
S1E5 / 17 May 2010
Planets
S1E6 / 17 May 2010
Solar Systems
S1E7 / 24 May 2010
Moons
S1E8 / 24 May 2010
Season 2
Volcanoes - The Furnaces of Life
S2E1 / 11 Jul 2012
Megastorms - The Winds of Creation
S2E2 / 18 Jul 2012
Exoplanets - Planets from Hell
S2E3 / 25 Jul 2012
Megaflares - Cosmic Firestorms
S2E4 / 01 Aug 2012
Extreme Orbits - Clockwork and Creation
S2E5 / 08 Aug 2012
Comets - Frozen Wanderers
S2E6 / 15 Aug 2012
Asteroids - Worlds That Never Were
S2E7 / 22 Aug 2012
Birth of the Earth
S2E8 / 29 Aug 2012
Season 3
Journey from the Center of the Sun
S3E1 / 09 Jul 2014
The End of the Universe
S3E2 / 16 Jul 2014
Jupiter: Destroyer or Savior?
S3E3 / 23 Jul 2014
First Second of the Big Bang
S3E4 / 30 Jul 2014
Is Saturn Alive?
S3E5 / 06 Aug 2014
Weapons of Mass Extinction
S3E6 / 13 Aug 2014
Did a Black Hole Build the Milky Way?
S3E7 / 20 Aug 2014
Our Voyage to the Stars
S3E8 / 27 Aug 2014
The Search for a Second Earth
S3E9 / 03 Sep 2014
Season 4
How the Universe Built Your Car
S4E1 / 14 Jul 2015
Earth, Venus's Evil Twin
S4E2 / 21 Jul 2015
Monster Black Hole
S4E3 / 28 Jul 2015
Edge of the Solar System
S4E4 / 04 Aug 2015
Dawn Of Life
S4E5 / 11 Aug 2015
Secret History of the Moon
S4E6 / 18 Aug 2015
The First Oceans
S4E7 / 25 Aug 2015
Forces of Mass Construction
S4E8 / 01 Sep 2015
Season 5
Most Amazing Discoveries
S5E1 / 22 Nov 2016
Mystery of Planet 9
S5E2 / 29 Nov 2016
Black Holes: The Secret Origin
S5E3 / 06 Dec 2016
Secret History of Pluto
S5E4 / 03 Jan 2017
Stars That Kill
S5E5 / 10 Jan 2017
The Universe's Deadliest
S5E6 / 17 Jan 2017
Life and Death on the Red Planet
S5E7 / 24 Jan 2017
The Dark Matter Enigma
S5E8 / 31 Jan 2017
Strangest Alien Worlds
S5E9 / 07 Feb 2017
Season 6
Are Black Holes Real?
S6E1 / 09 Jan 2018
Twin Suns: The Alien Mysteries
S6E2 / 16 Jan 2018
Dark History of the Solar System
S6E3 / 23 Jan 2018
Death of the Milky Way
S6E4 / 30 Jan 2018
Uranus & Neptune: Rise of the Ice Giants
S6E5 / 06 Feb 2018
Secret History of Mercury
S6E6 / 13 Feb 2018
The Quasar Enigma
S6E7 / 20 Feb 2018
Strange Lives of Dwarf Planets
S6E8 / 27 Feb 2018
War on Asteroids
S6E9 / 06 Mar 2018
Mystery of Spacetime
S6E10 / 13 Mar 2018
Season 7
Nightmares of Neutron Stars
S7E1 / 08 Jan 2019
When Supernovas Strike
S7E2 / 15 Jan 2019
The Interstellar Mysteries
S7E3 / 22 Jan 2019
How Black Holes Made Us
S7E4 / 29 Jan 2019
Secret World of Nebulas
S7E5 / 05 Feb 2019
Did the Big Bang Really Happen?
S7E6 / 12 Feb 2019
Battle of the Dark Universe
S7E7 / 19 Feb 2019
Hunt for Alien Life
S7E8 / 26 Feb 2019
Finding the New Earth
S7E9 / 05 Mar 2019
Cassini's Final Secrets
S7E10 / 12 Mar 2019
Season 8
Asteroid Apocalypse: The New Threat
S8E1 / 02 Jan 2020
NASA's Journey to Mars
S8E2 / 09 Jan 2020
Hunt for Alien Evidence
S8E3 / 16 Jan 2020
Death of the Last Stars
S8E4 / 23 Jan 2020
Secrets of Time Travel
S8E5 / 30 Jan 2020
When NASA Met Jupiter
S8E6 / 06 Feb 2020
Edge of the Universe
S8E7 / 13 Feb 2020
Monsters of the Milky Way
S8E8 / 20 Feb 2020
Earth's Death Orbit
S8E9 / 27 Feb 2020
Season 9
Journey to a Black Hole
S9E1 / 24 Mar 2021
Mission to a Comet
S9E2 / 31 Mar 2021
Secrets Of The Sun
S9E3 / 07 Apr 2021
Aliens of the Microcosmos
S9E4 / 14 Apr 2021
Curse of the White Dwarf
S9E5 / 21 Apr 2021
War of the Galaxies
S9E6 / 28 Apr 2021
The Next Supernova
S9E7 / 05 May 2021
Secret Lives Of Neutrinos
S9E8 / 12 May 2021
Birth of Monster Black Holes
S9E9 / 19 May 2021
Gravitational Waves Revealed
S9E10 / 26 May 2021
Mystery of Alien Worlds
S9E11 / 02 Jun 2021
Season 10
Secrets of the Cosmic Web
S10E1 / 06 Mar 2022
Curse of the Cosmic Rays
S10E2 / 13 Mar 2022
Hunt for Dark Matter
S10E3 / 20 Mar 2022
Dark History of Earth
S10E4 / 27 Mar 2022
Hunt for the Universe's Origin
S10E5 / 03 Apr 2022
Voyager's Ultimate Mission
S10E6 / 10 Apr 2022
Season 11
The Moons of Saturn
S11E1 / 05 Mar 2023
A Robot's Guide to Mars
S11E2 / 12 Mar 2023
Most Violent Event in the Universe
S11E3 / 19 Mar 2023
Asteroid: Countdown to Catastrophe
S11E4 / 26 Mar 2023
Solar System Special
S11E5 / 02 Apr 2023
No crew information available.
