Carl Sagan's Cosmos Chapter 13 "Who Speaks for Earth?"
Sagan reflects on the future of humanity and the question of "who speaks
for Earth?" when meeting extraterrestrials. He discusses the very
different meetings of the Tlingit people and explorer Jean-François de La Pérouse with the destruction of the Aztecs by Spanish conquistadors, the looming threat of nuclear warfare, and the threats shown by his historically-inaccurate retelling of the destruction of the Library of Alexandria and the murder of Hypatia.
The episode ends with an overview of the beginning of the universe, the
evolution of life, and the accomplishments of humanity and makes a plea
to mankind to cherish life and continue its journey in the cosmos. The Cosmos Update notes the preliminary reconnaissance of planets with spacecraft, the fall of the Berlin Wall and the end of apartheid in South Africa, and measures towards the reduction of nuclear weapons.