David J. Helfand

饰：Himself - Quest University, Canada

Phil Plait

饰：Himself - Astronomer

Michelle Thaller

饰：Herself - Phd., astronomer, NASA Goddard Space Flight Center

Geoff Marcy

饰：Himself - University of California Berkeley

Bob Ballard

饰：Self - Oceanographer

Seth Shostak

饰：Self - SETI Institute

Fritz Coleman

饰：Self - Weather Forecaster, KNBC

Rosaly Lopes

饰：Self - Senior Research Scientist, JPL

Lynn Rothschild

饰：Self - NASA Ames Research Center

Russell Schweickart

饰：Self - Apollo 9 astronault

H. Jay Melosh

饰：Self - Planetary scientist, University of Arizona

乔治欧·A·索卡洛斯

Giorgio A. Tsoukalos

饰：Self - Publisher, Legendary Times Magazine

John Cornett

饰：Self - National Solar Observatory

Ed Krupp

饰：Self - Griffith Observatory

Ed Moses

饰：Self - National Ignition Facility