Neil deGrasse Tyson
Self - Host (26 eps)
Carl Sagan
Self (archive footage) (10 eps)
Seth MacFarlane
(voice) (4 eps)
Sasha Sagan
Rachel Molly Gruber (3 eps)
Stoney Emshwiller
Guard (voice) (2 eps)
André Sogliuzzo
Christopher Wren (voice) (2 eps)
Christopher Emerson
Acolyte (voice) (2 eps)
Piotr Michael
Edmund Muskie (voice) (2 eps)
Patrick Stewart
William Herschel (voice) (2 eps)
Elizardo Torrez
Young Carl Sagan (2 eps)
Trang Vo
(voice) (2 eps)
John Steven Rocha
Bellaramine (voice) (1 eps)
Paul Telfer
Angry Scholar #2 (voice) (1 eps)
Jonathan Morgan Heit
John Herschel (voice) (1 eps)
Cary Elwes
Edmond Halley / Robert Hooke (voice) (1 eps)
Tom Konkle
Samuel Pepys (voice) (1 eps)
Alexander Siddig
Isaac Newton (voice) (1 eps)
Alfred Molina
Ibn al-Haytham (voice) (1 eps)
Richard Gere
Clair Patterson (voice) (1 eps)
Marc Worden
Harrison Brown (voice) (1 eps)
Kirsten Dunst
Cecilia Payne (voice) (1 eps)
Marlee Matlin
Annie Jump Cannon (voice) (1 eps)
Peggy Jo Jacobs
Margaret Harwood (voice) (1 eps)
Amanda Seyfried
Marie Tharp (voice) (1 eps)
Christiane Amanpour
Enheduanna (voice) (1 eps)
Michael Chochol
Jan Oort (1 eps)
Oliver Vaquer
Joseph von Fraunhofer (voice) (1 eps)
Fred Tatasciore
Democritus (voice) (1 eps)
Martin Jarvis
Humphry Davy (voice) (1 eps)
Noah Langford
(voice) (1 eps)
Fay Masterson
(voice) (1 eps)
Heiko Obermöller
Einstein's Father (voice) (1 eps)
Julian Ovenden
Michael Faraday (voice) (1 eps)
Jack Rainsford
(voice) (1 eps)
Glenn Steinbaum
Bruce Heezen (voice) (1 eps)
William Salyers
(voice) (1 eps)
Paul Sorvino
Augustin Mouchot (voice) (1 eps)
Eliza Schneider
(voice) (1 eps)
Frank Baxter
Self (archive footage) (1 eps)
John F. Kennedy
Self (voice) (archive footage) (1 eps)
Masoumeh Husseini
Monk (voice) (1 eps)
Harssh A. Singh
Ashoka (voice) (1 eps)
Shereen Balles
Female Voyager (voice) (1 eps)
Kapeneta Te'o-Tafiti
Male Voyager (voice) (1 eps)
Joseph Grange
John Herschel (voice) (1 eps)
Carol Bach Rita
Caroline Herschel (voice) (1 eps)
Viggo Mortensen
Nikolai Vavilov (voice) (1 eps)
Ken Lally
(voice) (1 eps)
Phil Crowley
(voice) (1 eps)
Yuri Lowenthal
(voice) (1 eps)
Edita Brychta
(voice) (1 eps)
Christopher Lee Parson
(voice) (1 eps)
Andrew Pifko
(voice) (1 eps)
Brendan Bradley
(voice) (1 eps)
Matthew Jayson Cwern
(voice) (1 eps)
Alan Shearman
(voice) (1 eps)
Natasha Goubskaya
(voice) (1 eps)
Skye Sammoutis
(voice) (1 eps)
Marcelo Tubert
(voice) (1 eps)
Mara Junot
(voice) (1 eps)
Rick Pasqualone
(voice) (1 eps)
Elijah Braik
(voice) (1 eps)
Novi Brown
(voice) (1 eps)
Will Greenburg
John Goodricke (1 eps)
Steve Oatway
Charles Darwin (1 eps)
Adam Tsekhman
Christiaan Huygens (1 eps)
Neil Arnote
Neil Armstrong (1 eps)
Ernie Vigil
Thomas Young (1 eps)
Judd Hirsch
Robert Oppenheimer (voice) (1 eps)
Olivia d'Abo
Marie Curie (voice) (1 eps)
Yurika Okamura
(voice) (1 eps)
Selyna Chan
(voice) (1 eps)
Sianna Chan
(voice) (1 eps)
Joseph J. Micucci
Young Father (1 eps)
Lennard Ortmann
Albert Einstein (1 eps)
Alex Bartram
Samuel Sagan (1 eps)
Brannon Braga
World's Fair Attendee (1 eps)
Marcello Guedes
Young Neil deGrasse Tyson (1 eps)
Leandro Guedes
Young Stephen Joseph Tyson (1 eps)