Questions are raised about the search for intelligent life beyond the Earth, with UFOs and other close encounters refuted in favor of communications through SETI and radio telescope such as the Arecibo Observatory. The probability of technically advanced civilizations existing elsewhere in the Milky Way is interpreted using the Drake equation and a future hypothetical Encyclopedia Galactica is discussed as a repository of information about other worlds in the galaxy. The Cosmos Update notes that there have been fewer sightings of UFOs and more stories of abductions, while mentioning the META scanning the skies for signals.

Space colonization is no longer the fodder of science fiction, it is becoming a reality. Examine the efforts underway to establish a human colony on Mars, including how they plan to grow food, recycle wastewater and introduce greenhouse gases to revive the red planet and make it more habitable for humans. Cutting-edge computer graphics are used to bring the universe down to earth to show what life would be like on Mars, and to imagine what kind of life forms might evolve in alien atmospheres.

There is a hellish planet in our solar system; covered in thick dense clouds and roasted by colossal temperatures. It will be inevitable that the Earth will someday not only be like Venus, but actually put it to shame. A billion years from now, Earth's oceans will boil off, triggering a runaway greenhouse effect, and the temperature will be so high, its all surface will melt. In the distance future, Earth could be the evil twin of Venus. To understand how our world will be destroyed we need to look at what happened to Venus.

This episode explores the palaeogeography of Earth over millions of years, and its impact on the development of life on the planet. Tyson starts by explaining that the lignin-rich trees evolved in the Carboniferous era about 300 million ago, then explains on the nature of plate tectonics that would shape the landmasses of the world and the asteroid impact that initiated the Cretaceous–Paleogene extinction event, leaving small mammals as the dominate species on earth. Earth's landmasses are expected to change in the future and postulates what may be the next great extinction event.

In a far cry from the steamy jungles of Rwanda or the icy waters of the Arctic, British naturalist Sir David Attenborough has donned a necktie and met with US president Barack Obama to discuss climate change and the future of the planet. The two met at the White House — a place the naturalist had never yet explored — on Sir David's 89th birthday in May to film the interview". It was the first time the respected wildlife filmmaker had met an American president and he seemed a little awed by the experience. Mr Obama, who grew up watching Sir David's programs, seemed equally thrilled. The president has the environment and climate change on his radar and is anxious to see progress made as his presidency comes to a close. He faces stiff opposition from Republicans in Congress on his plans to tackle climate change, but remains determined to make changes before leaving office. "I don't have much patience for anyone who denies that this challenge is real," he said. "We don't have time for a meeting of the Flat Earth Society." Sir David, who has been called "the godfather of natural history TV" by the BBC, brought to the meeting six decades dedicated to sharing the wonders of the natural world with television audiences. After initially being rejected for television because his teeth were deemed "too big", Sir David went on to make his Life on Earth television series, which has been watched by more than 500 million people worldwide. His name is now synonymous with nature, conservation and wildlife. During the television interview, the men discussed global warming, renewable energy and how children and young people hold the key to reversing the damage.

Earth may seem like the most hospitable planet in the solar system. But look again. Startling new discoveries reveal the blue planet has been plagued by more chaos and destruction than scientists once imagined. Stand on the Earth billions of years ago as a primitive planet called Theia slams into it. Shiver as our entire globe is frozen over like a gigantic snowball. Feel the heat as mammoth volcanoes scorch the landscape and darken the sky. From a cosmic gamma ray burst frying away the ozone layer to an Everest-size asteroid slamming into the ocean, we'll reveal new information about how these unparalleled events drove life to the brink of total extinction. Out of this continuous devastation, how has our planet--and life--got to where it is today? Are the worst days behind us--or lurking in the distant future?