This is the famous episode on nuclear war in which Dr. Sagan argues that our responsibility for survival is owed not just to ourselves, but also to the cosmos, ancient and vast, from which we spring. watch
Are there alien intelligences? How could we communicate with them? The answers to these questions take us to Egypt to decode ancient hieroglyphics, and to the largest radio telescope on Earth. watch
The brain is the focus of this fascinating portion of our journey as Dr. Sagan examines another of the intelligent creatures with whom we share the planet Earth — whales. watch