To survive, animals need somewhere to live, a place that provides the necessities of life, shelter from the elements and a refuge from enemies. Good homes are rare and competition can be intense – finding a home is one thing, but defending it is quite another.

Brian asks how, from a lifeless cosmos, it is possible that a planet can produce the more than eight million species we know of.

Andrew Graham-Dixon explores how Russia changed from a feudal nation of aristocratic excess to a hotbed of revolution at the beginning of the 20th century and how art moved from being a servant of the state to an agent of its destruction. From monuments that celebrate the absolutism of the tsars to the epic Russian landscape as inspiration; from the design and construction of gold and glittering palaces to the minutiae of diamond-encrusted Faberge eggs; and eventually to the stark and radical paintings of the avant-garde, the journey through Russian art history is one of extraordinary beauty and surprise.

Is there another Earth out there with liquid oceans, rocky continents and life like us? Astronomers seek the answer with spectroscopy, direct imaging and telescopes. They hope to find evidence of atmospheres, magnetospheres and signs of life.

A group of Egyptian revolutionaries battle leaders and regimes, risking their lives to build a new society. The Egyptian Revolution has been an ongoing rollercoaster over the past two and a half years. Through the news, we only get a glimpse of the bloodiest battle, an election, or a million man march. At the beginning of July 2013, we witnessed the second president deposed within the space of three years. The Square is an immersive experience, transporting the viewer deeply into the intense emotional drama and personal stories behind the news. It is the inspirational story of young people claiming their rights, struggling through multiple forces: from a brutal army dictatorship willing to crush protesters with military tanks, to a corrupt Muslim Brotherhood using mosques to manipulate voters. Directed by Jehane Noujaim, the film was nominated for the Academy Award and also won three Emmy Awards.

The Search for Freedom is the story of a cultural revolution fueled by the human desire to live in the moment and do what makes you feel the most alive. DIrector Jon Long presents this visceral look at the pioneers of extreme sports, including skateboarder Danny Way and motobiker Robbie Madison, and the human stories behind their search for thrills.