This episode covers the nature of how life may have developed on Earth and the possibility of life on other planets. Tyson begins by explaining how the human development of writing systems enabled the transfer of information through generations, describing how Princess Enheduanna ca. 2280 BCE would be one of the first to sign her name to her works, and how Gilgamesh collected stories, including that of Utnapishtim documenting a great flood comparable to the story of Noah's Ark. Tyson explains how DNA similarly records information to propagate life, and postulates theories of how DNA originated on Earth, including evolution from a shallow tide pool, or from the ejecta of meteor collisions from other planets. In the latter case, Tyson explains how comparing the composition of the Nakhla meteorite in 1911 to results collected by the Viking program demonstrated that material from Mars could transit to Earth, and the ability of some microbes to survive the harsh conditions of space. With the motions of solar systems through the galaxy over billions of years, life could conceivably propagate from planet to planet in the same manner. Tyson then moves on to consider if life on other planets could exist. He explains how Project Diana performed in the 1960s showed that radio waves are able to travel in space, and that all of humanity's broadcast signals continue to radiate into space from our planet. Tyson notes that projects have since looked for similar signals potentially emanating from other solar systems. Tyson then explains that the development and lifespan of extraterrestrial civilizations must be considered for such detection to be realized. He notes that civilizations can be wiped out by cosmic events like supernovae, natural disasters such as the Toba disaster, or even self-destruct through war or other means, making probability estimates difficult. Tyson describes how elliptical galaxies, in which some of the oldest red dwarf stars exist, would offer the best chance of finding established civilizations. Tyson concludes that human intelligence properly applied should allow our species to avoid such disasters and enable us to migrate beyond the Earth before the Sun's eventual transformation into a red giant.

The centre of our galaxy is home to an invisible monster of unimaginable power – a supermassive black hole named Sagittarius A star, with four million times the mass of the Sun. Recent astronomical breakthroughs have confirmed not only that black holes like Sagittarius A star exist, but that these bizarre invisible objects may be the ultimate galactic protagonists.
Stunning CGI takes us back to witness the fiery origins of our galaxy’s black hole 13.6 billion years ago, when the early universe was home to colossal blue stars, and when they ran out of fuel, they collapsed under their own enormous mass, crushing down into an object so small and so dense it punched a hole in the fabric of the universe. Over billions of years, Sagittarius A star feasted on nearby gas, stars, and through cataclysmic mergers with other black holes. A breakthrough discovery by Nasa’s Fermi gamma-ray telescope has shown that our black hole had the power to sculpt the entire galaxy, creating vast bubbles of gas above and below our galaxy and even protecting stars systems as ours.
In a mind-bending conclusion, Brian Cox reveals how our modern understanding of black holes is challenging our concepts of reality to the breaking point. In trying to understand the fate of objects that fall into Sagittarius A star, scientists have come to a stunning conclusion: space and time, concepts so foundational to how we experience the world around us, are not as fundamental as we once thought.

Embark on an astounding journey across 100,000 light-years to witness key moments in the history of the Milky Way. Using cutting-edge science, National Geographic constructs a 3-D state-of-the-art CGI model of our galaxy. We'll peer into the heart of the Milky Way on the hunt for super-massive black holes, watch how stars are born and die, fly out and above the plane of our galaxy to understand its true shape and scour its dusty spiral arms for the possibility of life

Professor Brian Cox continues his epic exploration of the cosmos by looking at the faint band of light that sweeps across the night sky - our own galaxy, the Milky Way. The Sun is just one of almost 400 billion stars that form this vast, majestic disk of light, our own home in the universe. Thanks to a cutting-edge space we’re finally able to reveal the Milky Way’s dramatic history and predict its cataclysmic future.
Our galaxy started out a fraction of the size it is today, and Gaia telescope has revealed how it grew over the eons. Beautifully rendered VFX based on the very latest Gaia data has uncovered the remarkable story of our galaxy’s evolution. As our young galaxy encountered rival galaxies, it experienced a series of violent growth spurts and intense periods of cataclysmic change while battling to survive. Each time our galaxy feeds, a new era of star formation begins, fuelled by incoming torrents of fresh gas and energy. And there is another collision to come. Another, larger galaxy is coming our way. Andromeda is heading straight for us at a quarter of a million miles per hour. The Milky Way’s long-term fate is in the balance.

Is there anyone out there? Astronomers have been pointing their radio telescopes at the skies for decades trying to pick up alien signals, so far without success. But now there's a new way of looking for aliens. Hitch a ride with Dr Graham Philips as he joins astronomers trawling through the galaxy looking for signs of extra-terrestrial intelligence.

Our galaxy is one of hundreds of billions in the universe. View of universe through the Hubble telescope and go back almost all the way to the Big Bang.