Tyson describes the discovery of cosmic rays by Victor Hess through high-altitude balloon trips. Swiss Astronomer Fritz Zwicky, in studying supernovae, postulated that these cosmic rays originated from these events instead of electromagnetic radiation. Also tells how Vera Rubin observed that the rotation of stars at the edges of observable galaxies did not follow expected rotational behavior leading to consider the existence of dark matter. This further led to the discovery of dark energy to account for the increasing rate of expansion of the universe. Tyson then describes the interstellar travel of the two Voyager probes. Tyson tells the Carl Sagan's role in the Voyager program, including creating the Voyager Golden Record to encapsulate humanity and Earth's position in the universe. Tyson concludes the series by emphasizing Sagan's message on the human condition in the vastness of the cosmos, and to encourage viewers to continue to explore and discover what else the universe has to offer.

Following the wildly successful 'Cosmos: A Spacetime Odyssey,' Neil deGrasse Tyson returns as host to translate more revelations of science into a lavish transporting experience, taking audiences on a series of spiritual voyages of exploration. The show reveals previously uncharted realms, including lost worlds, worlds yet to come, and the worlds that humans may one day inhabit. Ann Druyan, original creative collaborator to Carl Sagan, whose iconic docuseries 'Cosmos' provided inspiration for this series, serves as executive producer alongside Seth MacFarlane.
Episode 1 takes viewers on a wild ride with the Ship of Imagination in an adventure spanning billions of years into the evolution of life.