Helen Czerski
В роли: Self - Presenter

Corinna Abesser
В роли: Self - Expert, chemistry of Earth atmosphere and water systems (как Dr. Corinna Abesser)

Bill Anders
В роли: Self - Apollo 8 Astronaught

Dale Gary
В роли: Self - Professor, Big Bear Solar Observatory (как Prof. Dale Gary)

Garry Hayes
В роли: Self - Geologist

David Margulies
В роли: Self - Artist, historian and devotee of blue

Stephen Mojzsis
В роли: Self - Professor of Geology, University of Colorado (как Prof. Steve Mojzsis)

George Rossman
В роли: Self - Geologist, California Institute of Technology (как Prof. George Rossman)

Brent Shock
В роли: Self - Gold prospector