Characters played by Erik Dellums
Narrator
Characters played by Hakeem Oluseyi
Self
Self - Astrophysicist
Characters played by Michael Massimino
Self - Astronaut and Host
Characters played by Erik Asphaug
Self - Planetary Scientist
Characters played by Dan Durda
Self - Planetary Scientist
Characters played by Nina Lanza
Self - Planetary Scientist
Characters played by Phil Plait
Self - Astronomer
Characters played by Jani Radebaugh
Self - Planetary Scientist
Characters played by Sean C. Soloman
Self - Messenger Principal Investigator
Characters played by Michelle Thaller
Self - Astronomer