The Planets

Erik Dellums

Self - Narrator

Hakeem Oluseyi

Self - Astrophysicist

Michael Massimino

Self - Astronaut and Host

Michelle Thaller

Self - Astronomer

Phil Plait

Self - Astronomer

Jani Radebaugh

Self - Planetary Scientist

Nina Lanza

Self - Planetary Scientist

Dan Durda

Self - Planetary Scientist

Erik Asphaug

Self - Planetary Scientist

Sean C. Soloman

Self - Messenger Principal Investigator