Beginning with the separation of the fuzzy thinking and pious fraud of astrology from the careful observations of astronomy, Sagan follows the development of astronomical observation. Beginning with constellations and ceremonial calendars (such as those of the Anasazi), the story moves to the debate between Earth and Sun-centered models: Ptolemy and the geocentric worldview, Copernicus' theory, the data-gathering of Tycho Brahe, and the achievements of Johannes Kepler (Kepler's laws of planetary motion and the first science-fiction novel).

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.

Hidden Kingdoms for the first time takes the viewer into a unique and unexplored miniature world, immersing you into the action-packed lives of the planet's smaller animals. This episode is the story of two young animals forced to grow up fast. In Africa's savannah, a baby elephant shrew learns how speed is the secret to survival amongst the largest animals on Earth; and in America, a young grasshopper mouse confronts the Wild West's deadliest creatures to stake a claim of his own

The third episode follows tigers, harpy eagles, chimpanzees, army ants and other predators as they rise to the challenge of hunting within the forest - a dense, confusing, three-dimensional world, one in which even finding prey is a maddening task. The prize for succeeding at nature's great game of hide-and-seek is one worth winning. Forests cover one third of the land surface, and concealed within are over half of the species on Earth.

Can skyscrapers be made safer, more efficient, and livable in our rapidly growing cities? Skyscrapers are gleaming symbols of prestige, and an ingenious way to save space in dense urban areas. But as buildings rise ever higher, what are the risks of these architectural behemoths?
Do we truly know how they will hold up in earthquakes, fires and wind? What have--or haven’t—we learned from past tragedies? But even as we devise ways to defend them against potential disasters, can we also make them more livable, interactive, and eco-friendly?

Did you know that 1% of the white noise you see on old televisions is background radiation from The Big Bang? That the gold on a wedding ring comes from a star that exploded 5 billion years ago? And, that we're connected to the salt water of the first oceans through the water in our bodies? Our human story is actually 14 billion years old and the clues are all around us. This CGI-driven special will tell the history of our world in two hours, an ambitious story that will give surprising connections to our daily lives. From the formation of the earth and the emergence of life, to the advance of man and the growth of civilization, it’s a rapid-fire view of our unforgettable story.