This episode includes footage of wildlife inhabiting underwater kelp forests, thousands of giant cuttlefish spawning along a restricted area of rocky reef off the south coast of Australia. Males outnumber females 11 to one, which leads to fierce competition. Larger males use brute force to drive off competition, while their smaller rivals use deception by mimicking the appearance of females. The programme also features tiger sharks hunting for green turtles in fields of seagrass and spider crabs trying to avoid predators while they shed their shells.

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.

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.

This is our home, the earth it's, it's the only place we've got. It is one strange rock because it's ours and we are here and we don't know if any other place in the universe, yet, that can support life. We're very lucky to have it as our home.
Astronauts including the legendary Peggy Whitson, who spent 665 days in space, speak about how their concepts of home have changed since their experience.

Sir David Attenborough investigates whether the world is heading for a population crisis. While much of the projected growth in human population is likely to come from the developing world, it is the lifestyle enjoyed by many in the West that has the most impact on the planet. Sir David examines whether it is the duty of individuals to commit not only to smaller families, but to change the way they live for the sake of humanity and planet Earth.

See as never before in this series the inner workings of our world, and explore black holes, supernovae, neutron stars, dark energy, and all the titanic forces that make us. A users guide to the cosmos from the big bang to galaxies, stars, planets and moons. Where did it all come from and how does it all fit together. A primer for anyone who has ever looked up at the night sky and wondered". Beneath the hood of your car lies the history of the Universe. The iron in your chassis, the gold in your stereo and the copper in your electronics all owe their existence to violent cosmic events that took place billions of years ago.