Looking back on the major stories of the year - from the New Horizons mission to the most distant world we have ever visited to the release of the first-ever picture of a black hole. The team relive the highlights and uncover the latest developments.

A new force threatens our perfect planet. In the past, five mass extinction events were caused by cataclysmic volcanic eruptions. It was not the lava or ash that wiped out life, but an invisible gas released by volcanoes: carbon dioxide. Almost every part of modern life depends on energy created by burning fossil fuels, and this produces CO2 in huge amounts. Humans are changing our planet so rapidly, it’s affecting earth’s life support systems: our weather, our oceans and the living world. The greatest change to be made is in how we create energy, and the planet is brimming with natural power that can help us do just that. It’s these forces of nature - the wind, the sun, waves and geothermal energy - that hold the key to our future.
Through compelling animal-led stories and expert interviews, we discover how CO2 is destabilising our planet. We meet rescued orphaned elephants in Kenya, victims of ever worsening droughts, and join ocean patrols off the coast of Gabon fighting to save endangered sharks. In the Amazon, we witness wildlife teams saving animals in the shrinking forests, and in San Diego we enter a cryogenic zoo preserving the DNA of endangered species before they become extinct.

We used to think that Earth was at the centre of the universe, but now we know we're not even at the centre of our own galaxy. Countless wonders exist between where earth is situated and the massive black hole at the galactic centre of our galaxy. Within the Milky Way can be found the debris of old, dying stars fuelling the birth of new stars and at the galactic centre hypervelocity stars get catapulted clear beyond the Milky Way's outer rim at unimaginable speeds. Come along for a guided tour of 100,000 light-year-wide family of stars and stellar phenomena we call The Milky Way.

Female Isisaurus traverse the Deccan Traps to reach their nesting site. A mixed herd of sauropods and Prenocephale navigate a maze of canyons, but are ambushed by a pack of Velociraptor and a trio of Tarbosaurus. A colony of male Corythoraptor protect their eggs from the scorching sun by day, and a female Kuru kulla at night, who has offpsring of her own.
Trudging through a scorching desert, two young Tarchia find relief at an oasis and encounter an adult twice their size, ready to lay claim. Several Isisaurus hatchlings fall prey to Rajasaurus in an attempt to reach their ancestral home.

Find out what is being done to prevent the end of the world from threats from outer space such as comets and asteroids. Also discussed are apocalyptic scenarios.

The Sun is a endless churning cauldron of nuclear reactions and our planet is at its mercy. Revealing its inner workings was once mission impossible, but not any more. We've recruited a fleet of spacecraft that monitor the Sun 24 hours a day, under close surveillance. We just might have what it takes to defend our planet.