Hubble: Secrets from Space Online

Martin Sheen - Self - Host (voice) , Alan Dressler - Self (as Professor Alan Dressler) , Ed Weiler - Self (as Professor Ed Weilier) , Lyman Spitzer - Self (as Professor Lyman Spitzer) , Bob O'Dell - Self (as Professor Bob O'Dell) , Chris Burrows - Self (as Professor Chris Burrows) , Jeff Hester - Self (as Professor Jeff Hester) , Holland Ford - Self (as Professor Holland Ford) , Paul Scowen - Self (as Professor Paul Scowen) , Heidi Hammel - Self (as Professor Heidi Hammel) , Sam Pascarelle - Self (as Professor Sam Pascarelle) , Mark Dickinson - Self (as Professor Mark Dickinson)