The theory of Némesis, a star that orbits the Sun and causes catastrophic events is explored. Nemesis is a hypothetical red dwarf or brown dwarf, originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years) somewhat beyond the Oort cloud, to explain a perceived cycle of mass extinctions in the geological record, which seem to occur more often at intervals of 26 million years.

The planets of our solar system have experienced epic catastrophes throughout their long history, both raining down from outside and bubbling up from within. We'll voyage back in time to investigate the violent events that profoundly shaped the planets, including earth itself. We'll witness stunning revelations about what transformed Mars into a barren, hostile desert... The disaster that changed Venus from temperate to hellish... The impact that blew away Mercury's mantle, turning it into a planetary core... A colossal disturbance that rearranged the orbits of the gas giants... Titanic impacts on Jupiter... And how a lost moon may finally explain Saturn's rings.

At 4.6 billion years old, the Solar System is our solid, secure home in the Universe. But how did it come to be? In this episode we trace the system's birth from a thin cloud of dust and gas. Shocked by a nearby supernova, the pull of gravity and natural rotation spun it into a flat disc from which the Sun and planets coalesced. It all happened in the space of 700 million years, during which the planets jockeyed for position, dodging the Late Heavy Bombardment of deadly asteroids and setting into the neat, stable system that we now realize might be a rarity in the universe.

What might happen if the first manned mission to Mars crashes hundreds of miles from the rocket that would take them back home? Could they survive the crash, and travel across the brutal Martian surface to their home ship? We'll show what the astronauts would have to do to survive dust storms and space radiation, while extracting vital resources like water from the Martian soil itself. It's a dramatic vision of the very near future, where survival can depend on pre-industrial technology and human ingenuity.

For thousands of years, humans have believed that there were once flying monsters. But did they really exist beyond our nightmares? 220 million years ago dinosaurs were beginning their domination of Earth. But another group of reptiles was about to make an extraordinary leap: pterosaurs were taking control of the skies. The story of how and why these mysterious creatures took to the air is more fantastical than any fiction. In Flying Monsters 3D, David Attenborough the worlds leading naturalist, sets out to uncover the truth about the enigmatic pterosaurs, whose wingspans of up to 40 feet were equal to that of a modern day jet plane. Attenborough works with scientists to understand the incredible story of the evolution of the pterosaurs, a story that unfolds in such stunning locations as New Mexico, the Jurassic Coast of Lyme Regis in Britain, an ancient pterosaur landing site in Southern France and a fossil pit in Germany where near perfect pterosaur specimens have been found. The central question and one of the greatest mysteries in palaeontology is: how and why did pterosaurs fly? How did lizards the size of giraffes defy gravity and soar through prehistoric skies? Driven by the information he finds as he attempts to answer these questions, Attenborough starts to unravel one of sciences more enduring mysteries, discovering that the marvel of pterosaur flight has evolutionary echoes that resonate even today. Flying Monsters 3D is a groundbreaking film that uses cutting-edge 3D technology and CGI to bring the story of giant flying monsters and their prehistoric world to life. Audiences of all ages will be in awe as they enter the world and experience, as never before, REAL Flying Monsters in 3D.

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?