The birth of our Solar System was both violent and chaotic. As planets formed around our Sun, gravity and luck determined their fate: some are tossed into the Sun, others thrown into interstellar space, never to return. It is survival of the fittest, on an interplanetary scale.
2017 • Astronomy
For centuries the giant planets floated on the fringes of the solar system as distant objects in the eyepieces of astronomers. But in December 1973 mankind had its first close encounter with Jupiter. We chart the story of our discovery of these massive planets, Jupiter, Saturn, Uranus and Neptune.
The United States and China are considering launching manned missions to Mars -- in 25 years. But Netherlands-based Mars One has a bold plan to land humans on Mars in 2027. Is the mission fuelled by wishful thinking and unproven science -- or will private explorations get us there?
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-Francois de La Perouse with the destruction of the Aztecs by Spanish conquistadors, the looming threat of nuclear warfare, and the threats shown by 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.