Guest Stars Grant Tremblay as Himself (Astrophysicist) Amber Straughn as Herself (Astrophysicist) Alex Filippenko as Himself (Astrophysicist) Sarah T. Stewart as Herself (Planetary Scientist) Lewis Dartnell as Himself (Astrobiologist) Michael R. Rampino as Himself (Geologist) Paul E. Olsen as Himself (Geologist)
