The very heart of Africa is covered in dense tropical rainforest. The animals that live here find the most ingenious ways to carve out their space in a claustrophobic landscape. Danger lurks in every shadow, but some animals thrive here, from honey-stealing chimps to birds with a lineage as old as the dinosaurs, thundering elephants and kick-boxing frogs. Here in the Congo, no matter how tough the competition, you must stand up and fight for yourself and your patch.

A constellation is a group of stars that are connected together to form a figure or picture. Explore some of the 88 official constellations and learn about some of the highlights of each.

Carl Sagan opens the program with a description of the cosmos and the Spaceship of the Imagination. The ship journeys through the universe's hundred billion galaxies, the Local Group, the Andromeda Galaxy, the Milky Way, the Orion Nebula, our Solar System, and finally the planet Earth. Eratosthenes' successful calculation of the circumference of Earth leads to a description of the ancient Library of Alexandria. Finally, the Ages of Science are described, before pulling back to the full span of the Cosmic Calendar.

Famed astrophysicist Neil deGrasse Tyson takes a tour of the Solar System and the known universe establishing the components of Earth's "address" within the Virgo Supercluster. He then shares the story of the person who championed an expansive understanding of Earth's place in the universe by presenting Renaissance Italian Giordano Bruno's vision of the universe as a limitless expanse of space and time. He then makes an exploration into the Cosmic Calendar, which dates back to the dawn of the Big Bang (similar to the presentation from episode 1 of the original series). The episode ends with deGrasse Tyson narrating how he met his mentor Carl Sagan, who hosted the first Cosmos series.

A stunning documentary about the escalating global nuclear arms crisis, Countdown to Zero is a fascinating and frightening exploration of the dangers of nuclear weapons, exposing a variety of present day threats and featuring insights from a host of international statesmen and experts. Among the voices are President Jimmy Carter, Mikhail Gorbachev, Pervez Musharraf, Tony Blair, former CIA Operations Officer Valerie Plame Wilson, the Ploughshares Fund’s Joe Cirincione and Stanford political scientist Scott Sagan. traces the history of the atomic bomb from its origins to the present state of global affairs: nine nations possessing nuclear weapons capabilities and others racing to join them, with the world held in a delicate balance that could be shattered by an act of terrorism, failed diplomacy, or a simple accident. It makes a compelling case for worldwide nuclear disarmament, an issue more topical than ever with President Obama and other world leaders working to revive this goal today. Written and directed by Lucy Walker, Countdown to Zero was screened for attendees of this year’s Global Zero International Conference in Paris and the TED Conference in Long Beach, California.

In the dark depths of the oceans, nearly 90% of all species light up the darkness from within. These creatures flash, sparkle, shimmer, or simply glow. Whether it’s to scare off predators, fish for prey, or lure a mate, the language of light is everywhere in the ocean depths, and scientists are finally starting to decode it. Discover surprising ways to harness nature’s light—from tracking cancer cells to detecting pollution, lighting up cities, and even illuminating the inner workings of our brains.