Series Cast 18

1. 

   Neil deGrasse Tyson

   Self - Host (20 Episodes)

2. 

   Lance Armstrong

   Self (1 Episode)

3. 

   Kareem Abdul-Jabbar

   Self (1 Episode)

4. 

   Jane Goodall

   Self (1 Episode)

5. 

   Katie Couric

   Self (1 Episode)

6. 

   Kevin Smith

   Self (1 Episode)

7. 

   Katy Perry

   Self (1 Episode)

8. 

   Sylvia Earle

   Self (1 Episode)

9. Fabien Cousteau

   Self (1 Episode)

10. 

    Adrian Grenier

    Self (1 Episode)

11. 

    James Cameron

    Self (1 Episode)

12. 

    Alan Alda

    Self (1 Episode)

13. 

    Stephen Colbert

    Self (1 Episode)

14. 

    Sam Harris

    Self (1 Episode)

15. 

    Frank Oz

    Self (1 Episode)

16. 

    Kelly Slater

    Self (1 Episode)

17. 

    Scott Kelly

    Self (1 Episode)

18. 

    Stephen Hawking

    Self (1 Episode)

Series Crew 0

There are no crew records added to Season 4.