鲁伯特·格雷夫斯

Rupert Graves

饰：Himself - Narrator

Robin Catchpole

饰：Himself - Astronomer, University of Cambridge

Steve Cowley

饰：Himself - United Kingdom Atomic Energy Authority

Francisco Diego

饰：Himself - Astronomer, University College London

Alex Filippenko

饰：Himself - Astrophysicist, University of California, Berkeley

Douglas Leonard

饰：Himself - Astrophysicist, San Deigo State University

Stephen Pumfrey

饰：Himself - Historian of Science, Lancaster University

Scott Sandford

饰：Himself - Astrochemist, NASA

Serena Viti

饰：Herself - Astrophysicist, University College London

弗雷德·霍伊尔

Fred Hoyle

饰：Self,(archive footage)

Alan Dressler

Alan Dressler

饰：Self - Astronomer, Carnegie Institution for Science,(as Dr Alan Dressler)