The black hole at the centre of the Milky Way is getting ready to feast. A gas cloud three times the size of our planet has strayed within the gravitational reach of our nearest supermassive black hole. And across the globe, telescopes are being trained on the heart of our Milky Way galaxy, some 27,000 light years from Earth, in the expectation of observing this unique cosmic spectacle. For cosmic detectives across the Earth, it is a unique opportunity. For the first time in the history of science, they hope to observe in action the awesome spectacle of a feeding supermassive black hole.

Travel to heart of the Sun, our star, a cauldron of superheated gases that writhe and contort along immense magnetic field lines. Discover how even life itself is forged in the heart of stars. We are made of stardust.

Sagan discusses comets and asteroids as planetary impactors, giving recent examples of the Tunguska event and a lunar impact described by Canterbury monks in 1178. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth's greenhouse effect. The Cosmos Update highlights the connection to global warming.

There is an extraordinary range of temperatures in the universe. This program examines the extreme lower temperature range, the temperature we live in and below, explaining how cold is essential for the formation of habitats suitable for life. Explore icy planets and moons, discover the role of cold in the Universe, and learn about the importance of ice to the development of habitable worlds.

Beneath Jupiter's swirling clouds lie our solar system's deepest secrets: from its violent youth, through the birth of life to the death of the sun. Now, scientists are unlocking these secrets and discovering that every living thing exists thanks to Jupiter.

The episode, devoted to the planet Mars, begins with scientific and fictional speculation about the Red Planet during the late nineteenth and early twentieth centuries (H. G. Wells' The War of the Worlds, Edgar Rice Burroughs' science fiction books, and Percival Lowell's false vision of canals on Mars). It then moves to Robert Goddard's early experiments in rocket-building, inspired by reading science fiction, and the work by Mars probes, including the Viking, searching for life on Mars. The episode ends with the possibility of the terraforming and colonization of Mars and a Cosmos Update on the relevance of Mars' environment to Earth's and the possibility of a manned mission to Mars.