Robert Brucato

饰：Self - Caltech Observatories

Ronald Florence

饰：Self - author

Wendy L. Freedman

饰：Self - Director, Carnegie Observatories

安德鲁·卡耐基

Andrew Carnegie

饰：Himself

George Ellery Hale

饰：Himself

Edwin Hubble

饰：Himself - astronomer

莫里斯·拉马奇

Maurice LaMarche

饰：Narrator

鲍勃·乔尔斯

Bob Joles

阿尔伯特·爱因斯坦

Albert Einstein

饰：Self,(archive footage)

Lowell Thomas

饰：Self,(archive footage)