The Search for Intelligent Life in the Universe

There is a growing conviction among some prominent scientists that we are not alone: elsewhere in the Universe there must be countless millions of other creatures unimaginably more intelligent than we are.
Where are they? What might they look like? How could we communicate with them?
Narrated by Carl Sagan of the Harvard Smithsonian Astrophysical Observatory.
Written by Carl Sagan and Philip Daly.
See page 59