Season 1, Episode 11 - "Next: 1—11 - The Immortals" - The Ship of the Imagination travels across the cosmos to discover the possibility of some beings that live forever and explain why other civilizations perish. Then, visit the Cosmic Calendar of the Future and contemplate what lies ahead with a hopeful vision.
Season 1, Episode 12 - "The World Set Free" - The journey starts with a trip to another world and time just before a runaway greenhouse effect causes havoc on the planet.
Season 1, Episode 13 - "Unafraid of the Dark" - A profile of the famous astronomer Fritz Zwicky.
There is a continuing season for this show! It's called Cosmos: Possible Worlds, hosted by the same person as before.