How the Universe Works The Mystery of Planet 9 (2010– ) Online
- Original Title :
- The Mystery of Planet 9
- Genre :
- TV Episode / Documentary
- Year :
- 2010–
- Cast :
- Mike Rowe,Mike Brown,Michelle Thaller
- Type :
- TV Episode
- Time :
- 43min
- Rating :
- 8.6/10
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.
| Episode cast overview: | |||
 | Mike Rowe | - | Himself - Narrator (voice) |
 | Mike Brown | - | Himself - Planetary Astronomer |
 | Michelle Thaller | - | Herself - Astronomer |
| Konstantin Batygin | - | Himself - Planetary Astrophysicist |
 | Phil Plait | - | Himself - Astronomer |
 | Lawrence Krauss | - | Himself - Cosmologist (as Lawrence M Krauss) |
| Kevin Walsh | - | Himself - Astronomer |
 | Jani Radebaugh | - | Herself - Planetary Scientist |
 | Dan Durda | - | Himself - Planetary Scientist |
| Hakeem Oluseyi | - | Himself - Astrophysicist |
| James S. Bullock | - | Himself - Astrophysicist (as James Bullock) |